2024-03-29T00:13:04Zhttps://kuscholarworks.ku.edu/oai/requestoai:kuscholarworks.ku.edu:1808/55182020-07-27T13:03:36Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2009-10-13T04:06:21Z
urn:hdl:1808/5518
GLYCOPEPTIDE ANALYSIS OF HIV-1 ENVELOPE PROTEIN USING HPLC/ESI-FTICR MS AND MALDI-TOF MS WITH ASIALOFETUIN ENRICHMENT AND SEPARATION TECHNIQUES
Chang, Qing
Desaire, Heather
Johnson, Michael
Mure, Minae
Chemistry
Glycosylation on proteins serve many biological roles and their heterogeneity can affect various biological functions. The site occupancy of the glycans as well as their various glycoforms makes glycans unique to analyze due to the fact that the variation in structure is not based on a genomic code. Glycosylation is a post-translational modification that provides diverse glycoforms. Mass spectrometry has become a standard technique for characterizing the site occupancy and glycoforms that a protein exhibits. Methodologies in characterization of glycopeptides often include a proteolytic digest followed by purification of the digested protein with liquid chromatography. Mass spectrometers are sensitive to salts and buffer contents, thus a purification of the sample before analysis is vital for the detection of the sample. The research presented herein studies the glycosylation coverage of two HIV-1 envelope proteins. The intention of this study is to determine the specific sites on the HIV-1 protein that are heavily masked/protected by glycans or are free of glycans, in order for future studies to correlate if exposed regions on the protein are favorable regions for vaccine design. Another study was performed to aid in the glycosylation analysis of the HIV-1 proteins. Asialofetuin was used as a model protein to scrutinize the separation efficiencies of three various capillary columns. Specifically the separation of glycopeptides from a peptide mixture was conducted on the three columns in order to determine which platform would optimize the separation of N-linked HIV glycopeptides from a peptide mixture.
2009-10-13T04:06:21Z
2009-10-13T04:06:21Z
2009-04-28
2009
Thesis
http://dissertations.umi.com/ku:10320
http://hdl.handle.net/1808/5518
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/302282021-03-05T19:04:29Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-03-29T18:02:42Z
urn:hdl:1808/30228
Analyzing Extracellular Vesicles as Potential Biomarkers of Stroke Using Polymer Microfluidic Devices
Wijerathne, Harshani Nayomi
Soper, Prof. Steven A
Lunte, Prof. Susan
Dunn, Prof. Robert
Benson, Prof. David
Friss, Prof. Liza
Analytical chemistry
Biochemistry
Droplet digital PCR
Extracellular vesicles
Ischemic stroke
Microfluidics
Nanoparticle tracking analysis
Transmission Electron Microscopy
A major drawback of currently available stroke diagnosis methods, such as computed tomography (CT) and magnetic resonance (MRI), is that they cannot provide timely diagnosis within the narrow therapeutic time window of 4.5 h from stroke onset afforded by recombi-nant tissue plasminogen activator treatment. Upon initiation of a stroke event, CD15+ neu-trophils and CD8+ T cells are recruited and activated in response to the inflammatory stroke event and can release into blood extracellular vesicles (EVs) containing mRNA markers with altered expression profiles indicative of tissue damage. Our previous studies demonstrated that certain leukocyte subpopulations and gene expression profiling of these isolated sub-populations could be used to diagnose acute ischemic stroke (AIS) within 3 h. Here, our re-search goal was to develop a novel approach for the measurement of mRNA transcripts in EVs rather than cells as a possible diagnostic for AIS. To facilitate the development of the AIS diagnostic based on EVs, we developed a microfluidic device with a high-density array of antibody-modified micropillars for the affinity selection of CD8+ or CD15+ EVs with an analysis time less than the 4.5 h recombinant tissue plasminogen activator effective therapeu-tic time window. We successfully developed a microfluidic device with a high-density array of anti-body-modified micropillars for the affinity selection of CD8+ EVs, which could process 200 µL of plasma in 90%. Initial validation of these devices was per-formed using a model cell line Molt-3, which contained CD8+ T-cells. With the aid of fluo-rescence microscopy, we demonstrated that EVs can be affinity selected using the microflu-idic device with higher specificity compared to other EV isolation techniques, such as ul-trancentrifugation or PEG-precipitation that can improve the quality of the mRNA expression data. Transmission Electron Microscopy (TEM) and Nano Particle Tracking Analysis (NTA) revealed that the microfluidic device was capable of capturing and releasing enriched EVs with a short analysis time (<25 min). Gene expression analysis performed via droplet digital PCR revealed that for AIS, the genes we selected (PLBD1, MMP9, VCAN, FOS, CA4) pro-duce similar expression between the CD8+ T cells and EVs originating from these cells. The analysis of clinical samples, which used a 7-bed microfluidic device with 10 µm pillars and an interpillar spacing of 10 µm provided a higher dynamic range compared to a 3-bed device that used larger pillars (~90 µm) as well as significantly reduced processing time. In a blinded study performed for healthy and AIS patient samples, we were able to correctly identify 4/5 stroke patient samples and 4/5 healthy control samples. Although results reported here are very encouraging, more extensive studies are needed with a larger cohort of patient samples and healthy controls to clearly determine receiver operating characteristics for the use of EVs as a source of mRNA for AIS diagnosis. The research work I conducted on identification of mutations stabilizing Bacterioferritin associated ferredoxin is included in Appendix.
2020-03-29T18:02:42Z
2020-03-29T18:02:42Z
2019-08-31
2019
Dissertation
http://dissertations.umi.com/ku:16763
http://hdl.handle.net/1808/30228
https://orcid.org/0000-0002-9921-0731
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/122912020-10-06T13:53:59Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2013-09-29T17:56:18Z
urn:hdl:1808/12291
Development of Dual-Electrode Amperometric Detectors for Liquid Chromatography and Capillary Electrophoresis
Dorris, Megan
Lunte, Craig E.
Lunte, Susan M.
Rivera, Mario
Johnson, Michael
Scott, Emily E.
Analytical chemistry
Chemistry
Amperometric
Capillary electrophoresis
Dual electrode
Liquid chromatography
Abstract The body of this research was focused on the use and development dual-electrode detection schemes for liquid chromatography and capillary electrophoresis. These detection schemes were developed to investigate redox chemistries for endogenous and exogenous antioxidants that play key roles in maintaining tissue redox homeostasis under oxidative stress conditions. A parallel adjacent dual electrode detector was first proposed for liquid chromatography in which redox cycling was hypothesized to occur between the electrodes resulting in signal enhancement. Flow rates for these systems were too high (≥ 1.0 mL) to obtain redox cycling and subsequently no signal enhancement was observed for these systems. Flow rates in capillary electrophoresis are significantly lower compared to liquid chromatography. Therefore, a parallel dual–electrode was developed for capillary electrophoresis in this work. The dual–electrode was investigated using reduced phenolic acids, which were chemically reversible, semi–reversible and non-reversible compounds allowing all potential electrochemistry’s to be investigated. Redox cycling and signal enhancement was observed with the developed dual–electrode. Furthermore, the parallel dual–electrode could be operated in either a redox cycling mode or dual–potential mode, where either chemical reversibility or voltammetry could be used as a means to confirm migration based peak identification, respectively. The same design was then applied for a dual Au/Hg electrode for capillary electrophoresis, in which thiols and disulfides were investigated in vivo. With the developed dual Au/Hg electrode redox changes were observed as a result of chemically induced oxidative stress.
2013-09-29T17:56:18Z
2013-09-29T17:56:18Z
2013-05-31
2013
Dissertation
http://dissertations.umi.com/ku:12617
http://hdl.handle.net/1808/12291
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/42112020-07-21T13:06:45Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2008-09-29T03:45:26Z
urn:hdl:1808/4211
Charge Transfer Reactions in Porous Materials
Mitchell-Koch, Katie Rose
Thompson, Ward H
Barybin, Mikhail V.
Laird, Brian B
Tunge, Jon A
Scurto, Aaron M
Physical chemistry
Porous materials, such as sol-gels and zeolites, contain nanometer-scale spaces in which molecules are confined, leading to significant changes in their chemical dynamics. In this dissertation, the effects of confinement on chemical behavior are studied. By understanding how the properties of a material affect functionality, the rational design of porous materials for applications such as catalysis may be achieved. The study of entropy and free energy of a nanoconfined model dye molecule with Monte Carlo methods is discussed in Chapter 2. In Chapter 3, infrared spectra of a model proton-transfer complex calculated using mixed quantum-classical molecular dynamics are calculated. These studies indicate that charge transfer dynamics and equilibria are spatially-dependent in nanoconfined systems. This is reflected in the time-dependent fluorescence and infrared spectra, discussed in Chapters 2 and 3, respectively. Chapter 4 describes quantum chemical studies of a carbon acid being developed for use in Friedel-Crafts acylation as a solid acid catalyst.
2008-09-29T03:45:26Z
2008-09-29T03:45:26Z
2008-08-15
2008
Dissertation
http://dissertations2.umi.com/ku:2689
http://hdl.handle.net/1808/4211
https://orcid.org/0000-0002-9173-3677
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/123312020-09-25T14:34:54Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2013-09-30T20:12:14Z
urn:hdl:1808/12331
Conformational Analysis of Disordered Proteins Using H/D Exchange Mass Spectrometry
Keppel, Theodore Robert
Weis, David
Desaire, Heather
Rivera, Mario
Johnson, Carey K
De Guzman, Roberto
Analytical chemistry
Disordered proteins
Hdx
Lc-ms
Mass spectrometry
Protein
Intrinsically disordered proteins (IDPs) represent a growing area of scientific interest. The prevalence of IDPs within the proteomes of complex organisms and the importance of these proteins in cellular functions has become apparent. The application of hydrogen/deuterium exchange mass spectrometry (H/D-MS) to study IDPs is presented in this dissertation. Results that demonstrate improvements to the H/D-MS method are also presented. A thermoelectrically cooled refrigeration system was developed in order to house LC components necessary for bottom-up H/D-MS. This system was used to keep solvent temperatures low and stable, ensuring reproducible and minimized back exchange. Two model IDPs, the interacting domains of CREB binding protein (CBP, residues 2059-2117) and activator of thyroid and retinoid receptors (ACTR, residues 1018-1088), were analyzed using H/D-MS. CBP and ACTR represent two classes of IDPs: the molten globule and random coil, respectively. The mutual synergistic folding phenomenon observed when a complex is formed between these two proteins was also analyzed. A lower limit of several seconds of D2O exposure time is imposed when manual pipetting is used to add label and quench buffers to protein samples. A quench flow apparatus was used to extend the lower time scale limit of exposure times to 42 milliseconds. When CBP and ACTR were labeled using the quench flow apparatus, analyses revealed subtle exchange protection in specific regions of both proteins. An H/D-MS study of the conformational dynamics of β-glucuronidase was also conducted. The destabilization of β-glucuronidase that results from the W492G mutation and the partial conformational rescue that results from indole addition were analyzed. A new method to interpret and normalize H/D-MS data was introduced to improve intra- and inter-laboratory comparability.
2013-09-30T20:12:14Z
2013-09-30T20:12:14Z
2013-05-31
2013
Dissertation
http://dissertations.umi.com/ku:12598
http://hdl.handle.net/1808/12331
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/217072018-01-31T20:07:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2016-10-12T03:06:09Z
urn:hdl:1808/21707
New Methods for Palladium-catalyzed Decarboxylative Benzylation, Arylation and Dearomatization Reactions
Mendis, Ranasingha A. Shehani. N.
Tunge, Jon A
Hanson, Paul R
Malinakova, Helena C
Barybin, Mikhail V
Altman, Ryan
Organic chemistry
arylation
benzylation
catalyzed
dearomatization
decarboxylation
palladium
Development of novel synthetic methods for the efficient generation of new carbon-carbon bonds is a valuable endeavor in organic synthesis. In this regard, palladium-catalyzed decarboxylative cross-coupling has significant potential as a waste-free reaction manifold with increased functional group tolerance due to the avoidance of preformed organometallics and basic reagents. Since the initial reports by Saegusa and Tsuji on decarboxylative allylation (DcA) of β-ketoesters in 1980, this concept remained relatively unexplored until the independent reports from Tunge and Stoltz in 2004. Since then, couplings of a broad array of nucleophiles, as well as asymmetric variants of the DcA reactions, have been heavily developed. However, due to the inherently low reactivity of benzyl electrophiles, catalytic decarboxylative benzylation reactions are comparatively less developed. Presented herein are the developments of new methods for the catalytic decarboxylative benzylic cross-coupling reactions with weakly-stabilized nucleophiles. In particular, the benzyl alkyne cross-coupling, which was initially limited to extended aryl systems, was further developed to allow couplings of primary benzyl electrophiles without extended π-conjugation. Our efforts were then directed toward developing a highly stereospecific decarboxylative coupling of acetylides and ketone enolates with secondary benzyl electrophiles that possess a 1,1-diarylmethane structure. The coupling of secondary benzyl electrophiles with acetylides proceeded with high stereospecificity to provide enantioenriched 1,1-diarylethynyl methanes, and we are unaware of any other method for the direct synthesis of such motifs. However, racemization was observed in the decarboxylative coupling of enantioenriched benzylic β-ketoesters. In the search for a new method to couple secondary benzyl electrophiles with ketone enolates, we serendipitously discovered the unprecedented catalytic decarboxylative dearomatization and arylation reactions of ketone enolates. Two sets of protocols involving simple variation of ligands were then developed for the selective decarboxylative dearomatization or arylation of enolates. These methods provided alicyclic and mono-α-arylated ketones in a highly regioselective manner and the expected benzylation of ketone enolates was never observed. Additionally, initial results have also shown that the palladium-catalyzed decarboxylative dearomatization of benzyl carbonates is highly stereospecific.
2016-10-12T03:06:09Z
2016-10-12T03:06:09Z
2015-12-31
2015
Dissertation
http://dissertations.umi.com/ku:14273
http://hdl.handle.net/1808/21707
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/104592020-06-22T19:24:15Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2012-11-26T22:16:30Z
urn:hdl:1808/10459
Investigations into Protein-Surface Interactions via Atomic Force Microscopy and Surface Plasmon Resonance
Settle, Jenifer K.
Berrie, Cindy L.
Berrie, Cindy L.
Desaire, Heather
Dunn, Robert C.
Lunte, Craig E.
Williams, Susan M.
Analytical chemistry
Protein surface interactions are important in many diverse applications. In this dissertation nonspecific and specific interactions of two proteins (fibrinogen and F1-ATP synthase) with a variety of surfaces have been investigated via atomic force microscopy and surface plasmon resonance. Chapter one provides background information on protein surfaces interactions. Chapter 2 summarizes the techniques and surfaces utilized in the investigations in the following chapters. Chapter 3 provides background and investigations on nonspecific fibrinogen to surfaces. Fibrinogen is an important plasma protein involved in the blood clotting cascade. To improve design of materials for biodevices and implants, more knowledge about the interactions controlling fibrinogen adsorption is essential. Nonspecific adsorption of fibrinogen was investigated on model surfaces of graphite and mica as well as on self-assembled monolayer (SAM) via atomic force microscopy (AFM) to determine conformation. Complementary studies were performed via surface plasmon resonance (SPR) to investigate the dynamics of this adsorption process on gold, and an amine-, carboxyl-, methyl- and hydroxyl-terminated SAM films. Chapter 4 provides background and investigation into F1-Adenosine triphosphate synthase (ATPase) adsorption to surfaces. ATPase is a tiny molecular motor which synthesizes ATP. This motor is of interest in the fabrication of hybrid nanobiodevices. Incorporation of this protein into devices requires precise control over immobilization properties such as location, concentration, orientation, and function. Orientation of ATPase adsorbed nonspecifically on a mica surface was observed via AFM. Control over placement within the device was investigated via nanopatterning of a 1-dodecene SAM surface. Control over orientation was performed via engineering a landing pad within a resist matrix with AFM. This involved patterning a dithiol into a methyl resist matrix and addition of maleimide-NTA with coordination to nickel ions and histidine tags in the protein. The chemistry of this process was validated with SPR and fluorescence microscopy. Information on the kinetic of ATPase-his binding to the NTA surface was obtained. Hopefully information learned from these investigations enables the development of enhanced biocompatible materials design and control over the fabrication of functional hybrid nanobiodevices.
2012-11-26T22:16:30Z
2012-11-26T22:16:30Z
2012-08-31
2012
Dissertation
http://dissertations.umi.com/ku:12385
http://hdl.handle.net/1808/10459
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/77252020-08-06T13:45:23Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2011-07-04T17:51:34Z
urn:hdl:1808/7725
Investigation of Carbamathione Pharmacokinetics and Pharmacodynamics by In Vivo Microdialysis and Capillary Electrophoresis
Kaul, Swetha
Lunte, Craig E.
Faiman, Morris D
Lunte, Susan M.
Johnson, Michael
Hanson, Paul R.
Williams, Todd D
Analytical chemistry
Pharmacology
Neurosciences
Carbamathione
Disulfiram
Electrophoresis
Fluorescence
Microdialysis
Neurotransmitters
The pharmacological basis for the use of the drug disulfiram for alcoholism is its inhibition of liver aldehyde dehydrogenase (ALDH2). Recent studies have reported that disulfiram exhibited an anti-craving effect with both alcohol addiction and cocaine dependence. Inhibition of ALDH2 cannot explain disulfiram's efficacy in cocaine dependence. The disulfiram metabolite S-(N, N-diethylcarbamoyl) glutathione (carbamathione) is formed from disulfiram and appears in the brain after the administration of disulfiram. Carbamathione has no effect on liver ALDH2 and is a partial non-competitive inhibitor of the N-methyl-D-aspartic acid (NMDA) glutamate receptor. The effect of carbamathione on the neurotransmitter systems involved in craving and addiction is unknown. The aim of this research project was to develop analytical methods to determine carbamathione and relevant neurotransmitters in rat brain microdialysis samples in order to elucidate the pharmacokinetics and pharmacodynamics of carbamathione. The effect of disulfiram on the brain neurotransmitters was evaluated. The significance of this research is that carbamathione may be involved in the anti-craving effect observed with disulfiram, and thus may be used as a pharmacological tool to improve the effectiveness of disulfiram therapy in cocaine and alcohol addiction.
2011-07-04T17:51:34Z
2011-07-04T17:51:34Z
2010-11-10
2010
Dissertation
http://dissertations.umi.com/ku:11183
http://hdl.handle.net/1808/7725
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/88672019-07-26T18:20:21Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2012-04-11T13:33:18Z
urn:hdl:1808/8867
The Optical Properties of Some Petroleum Products
Humphrey, Irvin W.
2012-04-11T13:33:18Z
2012-04-11T13:33:18Z
1913-05-15
Thesis
http://hdl.handle.net/1808/8867
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/293072020-07-09T20:56:43Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2019-06-12T02:53:05Z
urn:hdl:1808/29307
Kinetic and Spectroscopic Investigation of Structural Influences on Hydrogen-atom Transfer Reactivity of N5-Ligated Oxomanganese(IV) Complexes
Massie, Allyssa A
Jackson, Timothy A
Barybin, Mikhail V
Blakemore, James D
Caricato, Marco
Allgeier, Alan M
Inorganic chemistry
Bioinorganic Chemistry
High-Valent Metal Oxos
Hydrogen Atom Transfer
Manganese
High valent iron- and manganese-oxo intermediates perform important hydrogenatom transfer (HAT) reactions in both biological and synthetic systems. There has been extensive characterization of HAT reactivity of enzymatic and synthetic oxoiron(IV) species, and these complexes have been shown to cleave a wide range of C-H bonds. Although there is no evidence for this type of reactivity by manganese enzymes in nature, several synthetic oxomanganese(IV) species are also capable of activating C-H bonds. However, whereas oxoiron(IV) species have been extensively characterized, the factors that influence HAT reactivity of oxomanganese(IV) species is poorly understood. In an effort to further understand the structure-reactivity relationship of oxomanganese(IV) species, a series of novel oxomanganese(IV) species with subtle perturbations to the equatorial ligand field of the neutral, pentadentate supporting ligand were prepared. Extensive spectroscopic studies, including structural characterization by X-ray absorption spectroscopy (XAS), revealed very minor geometric and electronic structure changes. Kinetic studies of C-H bond containing substrates offered insight into the effects of the ligand perturbations on the reactivity of these oxomanganese(IV) species. Electron donation from the supporting ligand decreases the rate of C-H activation. Conversely, weakening the ligand field through the use of a bulkier ligand dramatically speeds up HAT reactivity, allowing for the reaction with the strong C-H bonds of cyclohexane at rates exceeding that of oxoiron(IV) species with similar ligands. Further, it was discovered that the reaction with cyclohexane could be carried out catalytically in the presence of excess oxidant. The products of catalytic cyclohexane oxidation, cyclohexanol and cyclohexanone, provided evidence of the ability of this oxomanganese(IV) species to perform substrate hydroxylation. Lastly, peroxomanganese(III) species are proposed to be important intermediates in many biological systems. However, in both biological and synthetic systems, the factors that determine the cleavage of the O-O versus Mn-O bonds are not well understood. A novel peroxomanganese(III) species was prepared using electrochemically generated superoxide. The electrochemical reduction of this species was probed to further understand the effects of supporting ligand, which has an amide group trans to the peroxo.
2019-06-12T02:53:05Z
2019-06-12T02:53:05Z
2018-05-31
2018
Dissertation
http://dissertations.umi.com/ku:15898
http://hdl.handle.net/1808/29307
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/205322021-08-26T20:37:58Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-03-18T16:18:10Z
urn:hdl:1808/20532
The action of ethylene bromide on certain substituted thioureas
Miller, Alfred W.
Thesis (M.S.)--University of Kansas, Chemistry, 1923.
2016-03-18T16:18:10Z
2016-03-18T16:18:10Z
1923
Thesis
http://hdl.handle.net/1808/20532
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/315002021-03-05T16:53:01Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2021-02-27T20:58:40Z
urn:hdl:1808/31500
Experimental and Theoretical Study of Resonance Raman Spectroscopy in Ground and Excited Electronic States
Barclay, Matthew
Elles, Christopher G.
Caricato, Marco
Johnson, Carey K.
Thompson, Ward H.
Laird, Brian B.
Marshall, Craig P.
Physical chemistry
Computational chemistry
conjugated molecules
excited state
Raman spectroscopy
resonance Raman spectroscopy
thiophene
Spectroscopy is a powerful tool for the identification, study, and selective control of molecular processes. Raman scattering is particularly useful in observing the vibrational properties of molecules, and identifying compounds based on structure. While the experimental measurements provide structural information on the vibrational transitions, the detailed interpretation of Raman spectra for complex molecules requires assignment of the observed Raman bands to specific vibrational motions. As a result, experimental spectra are often compared with calculated vibrational frequencies and Raman intensities. Therefore, it is necessary that the simulated spectra correctly reproduce the experimental Raman spectra. Although simulations of Raman spectra generally have good agreement with experiment, additional work is required to understand the effects of intramolecular electronic and nuclear structure on the Raman intensities of molecules with extended π conjugation. Conjugated thiophene derivatives have a variety of interesting optical and electronic properties, which makes them ideal targets for studies of charge-transport processes. Additionally, the delocalized π electron distribution gives these compounds relatively large scattering cross-sections, making them excellent model compounds for Raman spectroscopic studies. In particular, time-resolved techniques are able to measure transient Raman spectra in electronically excited states, allowing for the direct observation of structural dynamics following optical excitation, which is instrumental in understanding the charge separation processes in these molecules. Due to small excited-state population, transient Raman measurements typically rely on electronic resonance enhancement, which increases the Raman transition intensities for specific vibrational modes by up to several orders of magnitude. This mode-specific enhancement occurs for vibrations with large displacements along the potential energy surfaces of the higher-lying electronic states, therefore, detailed information can be obtained about the structure of higher-lying states based on which vibrations have enhanced Raman scattering intensity. Although resonance-enhanced excited-state Raman measurements are often used to increase signal, the role of the resonant electronic transition has been largely overlooked. By combining experimental measurements and theoretical simulations of excited-state Raman spectra, it is possible to gain a more comprehensive understanding of the structure of the higher-lying electronic states. In this dissertation, we measured resonance-enhanced Raman spectra in excited singlet and triplet electronic states for a set of conjugated thiophene derivatives, and compared the experiments with calculated Raman intensities for the excited states. Using relatively inexpensive computational methods, we were able to assign the experimental Raman bands to specific vibrational motions by considering the resonance enhancement condition in detail. Additionally, it was found that the experimental resonance Raman intensities can be qualitatively reproduced by calculations of the energy gradient of the higher-lying electronic state along vibrational displacements, particularly for vibrations that have relatively large resonance enhancements. We also investigated the effect of inter-ring torsion on the Raman intensities of aryl-substituted benzene and thiophene compounds in the ground state, for which density functional theory calculations tend to overestimate the delocalization of the π electron distribution between aryl rings. In addition to providing a benchmark for the accuracy of theoretical methods, the combination of experimental and simulated Raman spectra provided more detailed insight into the electronic and structural properties of the conjugated thiophene molecules than could be obtained by either approach alone. Finally, we studied the excited-state dynamics of 2,5-diphenylthiophene (DPT) following photoexcitation. We found that, by examining the potential energy gradients of higher-lying electronic states, it was possible to characterize vibrational coherences observed in the excited-state absorption spectrum, ultimately providing a more complete interpretation of the excited-state dynamics of this model compound.
2021-02-27T20:58:40Z
2021-02-27T20:58:40Z
2019-12-31
2019
Dissertation
http://dissertations.umi.com/ku:16952
http://hdl.handle.net/1808/31500
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/264432018-06-02T08:02:24Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-06-01T15:03:29Z
urn:hdl:1808/26443
The preparation of a solid rhenide
Bravo, Justo Baladjay
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1953.
2018-06-01T15:03:29Z
2018-06-01T15:03:29Z
1953
Dissertation
http://hdl.handle.net/1808/26443
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/41812020-07-21T16:01:56Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2008-09-15T04:00:05Z
urn:hdl:1808/4181
Structure and Dynamic Studies of the Nuclear Pore Complex at the Single-Molecule Level
Dickenson, Nicholas E.
Dunn, Robert C
Lunte, Craig E
Desaire, Heather
Johnson, Michael A
Picking, William D
Analytical chemistry
Physical chemistry
Near-field
Nsom
Fret
Nuclear pore complex
Npc
Vault ribonucleoprotein
Single-molecule
Nuclear pore complexes (NPCs) are large macromolecular structures forming the only known direct route across the double bilayer membrane of the nuclear envelope. The NPC structure has been extensively explored in an effort to elucidate the mechanisms by which they control transport. Many of these studies have found the presence of a central mass or plug within the central channel of NPCs, although neither the function nor identity of the central mass were clear. Here, several techniques including electron microscopy, Förster resonance energy transfer (FRET), and high-resolution near-field scanning optical microscopy (NSOM) are utilized to specifically locate vault ribonucleoproteins to NPCs. This interaction, along with several other results, strongly suggests that vaults represent the central mass of NPCs. A single-molecule transport assay was also developed in order to record the translocation of individual fluorescent dextrans through NPCs. Comparison of the single-molecule dwell times under various conditions led to a better understanding of the specific mechanism controlling the non signal-mediated transport of cargo through NPCs.
2008-09-15T04:00:05Z
2008-09-15T04:00:05Z
2008-08-06
2008
Dissertation
http://dissertations2.umi.com/ku:2634
http://hdl.handle.net/1808/4181
https://orcid.org/0000-0003-1572-6077
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/87982020-09-03T14:34:25Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2012-03-07T16:47:16Z
urn:hdl:1808/8798
Fluorine In Water And Its Quantitative Determination
MacKinnon, A. R.
2012-03-07T16:47:16Z
2012-03-07T16:47:16Z
1912
Thesis
http://hdl.handle.net/1808/8798
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/184652017-12-08T21:34:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-09-21T18:30:24Z
urn:hdl:1808/18465
The dielectric constant of liquid ammonia
Latimer, Wendell Mitchell
Thesis (M.A.)--University of Kansas, Chemistry, 1917. ; Includes bibliographical references.
2015-09-21T18:30:24Z
2015-09-21T18:30:24Z
1917
Thesis
http://hdl.handle.net/1808/18465
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/187982017-12-08T21:34:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-11-03T14:48:58Z
urn:hdl:1808/18798
Synthesis and reactions of some thiazoles ; Thio-urea preparations
Harrel, Chastain Gaint
Includes bibliographical references.
2015-11-03T14:48:58Z
2015-11-03T14:48:58Z
1920
Thesis
http://hdl.handle.net/1808/18798
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/191252017-12-08T21:31:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-12-04T15:10:04Z
urn:hdl:1808/19125
Some halogen derivatives of aniline and the determination of chlorine and bromine in some organic compounds by the use of liquid ammonia
Vaughan, Tillman Herbert
Thesis (M.A.)--University of Kansas, Chemistry, 1916. ; Includes bibliographical references.
2015-12-04T15:10:04Z
2015-12-04T15:10:04Z
1916
Thesis
http://hdl.handle.net/1808/19125
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/41432018-01-31T20:07:56Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2008-09-08T01:26:16Z
urn:hdl:1808/4143
Phosphate Tethers in Synthesis: The Total Synthesis of Dolabelide C.
Waetzig, Joshua David
Hanson, Paul R.
Aube, Jeffrey
Carlson, Robert G.
Givens, Richard S
Tunge, Jon A
Organic chemistry
The utilization of phosphate tethers in synthesis is the focus of the dissertation research described herein. Specifically, cross metathesis of various olefin partners with a phosphate tether has been demonstrated. These studies established the Type III olefin reactivity of the exocyclic olefin of the triply allylic bicyclic phosphate tether. Cross metathesis between the bicyclic phosphate and complex olefin partners allowed for rapid assembly of advanced polyol subunits. Understanding the reactivity of the bicyclic phosphate allowed for the application of this methodology toward the synthesis of a natural product. The target chosen was dolabelide C, a 24-membered macrolactone possessing cytotoxicity against HeLa-S3 cervical cancer cells. Retrosynthetic analysis of dolabelide C revealed two subunits that could be accessed by the developed bicyclic phosphate tether methodologies. In the synthesis of the C1-C14 subunit of dolabelide C the bicyclic phosphate tether mediates a selective cross metathesis with the terminal exocyclic olefin, differentiates the endocyclic and exocyclic olefins for selective hydrogenation, and serves as a leaving grouping for a regioselective palladium(0)-catalyzed hydride opening. Upon removal of the phosphate tether, the C1-C14 subunit of dolabelide C was completed in six subsequent steps. Studies toward the C15-C30 subunit of dolabelide C also utilized the bicyclic phosphate tether methodology. Three routes toward this subunit were realized, each took advantage of the latent leaving group ability of the phosphate tether to set the C23 stereocenter. These sequences supplied the C15-C30 of dolabelide C which was then prepared for pairing with the C1-C14 subunit. Final coupling of the C1-C14 and C15-C30 subunits of dolabelide C was accomplished and five more steps were successfully achieved, culminating in a macrocyclic ring-closing metathesis to completed the total synthesis of dolabelide C. The total synthesis of dolabelide C using our temporary phosphate tether methods was achieved in 24 steps (longest linear sequence from acetylacetone) and 54 total steps. The overall yield for this synthesis was 0.73% with an average yield per chemical step being 81.5%.
2008-09-08T01:26:16Z
2008-09-08T01:26:16Z
2008-07-18
2008
Dissertation
http://dissertations.umi.com/ku:2411
http://hdl.handle.net/1808/4143
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/85282020-08-27T14:52:22Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2011-11-23T18:09:33Z
urn:hdl:1808/8528
Some Reactions of Formamidines
Malleis, Otto Oscar
2011-11-23T18:09:33Z
2011-11-23T18:09:33Z
1913-05-15
Thesis
http://hdl.handle.net/1808/8528
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/313722024-01-16T16:44:30Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2021-02-07T20:24:51Z
urn:hdl:1808/31372
Anion Relay Cyclopropanation and Aryl Vinyl Cyclopropane Cope Rearrangements
Allegre, Kevin Michael
Tunge, Jon A
Tunge, Jon A
Hanson, Paul R
Malinakova, Helena
Rubin, Michael
Altman, Ryan A
Organic chemistry
Anion Relay Chemistry
Aromatic
Cope Rearrangement
Cyclopropane
Retro-Claisen
Tsuji-Trost
Anion Relay Chemistry is a powerful tool for the rapid development of molecular complexity in an operationally simple manner. Much of the work in this field has been pioneered and developed by the Smith group, whose work has primarily focused on silicon and phosphorus Brook rearrangements to effect anion relay. Presented herein is the development of a retro-Claisen condensation protocol to effect anion relay in the synthesis of vinyl cyclopropanes, and subsequent aromatic Cope rearrangement of those vinyl cyclopropanes. This protocol provides a supplementary method of anion relay utilizing readily accessible nucleophiles, which obviates the need for synthesis of alkyl silanes or phosphines as starting materials. Chapter 1 is a review of anion relay chemistry, which focuses on through-space anion relay over 3 or more bonds. It covers both new developments and applications to total synthesis of through-space anion relay more than three bonds since the field was last reviewed by Smith in 2008. Chapter 2 begins with an overview of retro-Claisen activation of allylic alcohols and its application to decarboxylative and deacylative allylation reactions (DcA and DaA). This synopsis is followed by an overview of a novel anion relay cyclopropanation accomplished through a retro-Claisen activation of a nascent allylic alcohol following an initial Tsuji-Trost allylation between a carbon nucleophile and a vinyl epoxide. This reaction constitutes the latest example of retro-Claisen activation of allylic alcohols presented by our group, and a novel application of anion relay chemistry. Of note is that the anion relay is accomplished without a Brook rearrangement, obviating the necessity to synthesize alkyl silanes or phosphonates. Furthermore, it is an example of [1,6]-anion relay, examples of which are much less common than [1,2]-and [1,4]-anion relay. In chapter 3, aromatic vinyl cyclopropane Cope rearrangements are reviewed. This review is followed by a description of the aromatic Cope rearrangement of the vinyl cyclopropanes made using the methodologies outlined in Chapter 2. While divinyl cyclopropane Cope rearrangements are common and facile at room temperature, aryl vinyl cyclopropane Cope rearrangements are much less common, tend to require forcing conditions such as high temperatures and usually further require rigorously stereodefined starting materials to take advantage of the cyclopropane strain release to drive dearomatization. The reaction described in this document features a dynamic equilibrium of aryl vinyl cyclopropane diastereomers prior to Cope rearrangement, allowing the difficult Cope rearrangement to be accomplished even without stereodefined starting materials.
2021-02-07T20:24:51Z
2021-02-07T20:24:51Z
2019-08-31
2019
Dissertation
http://dissertations.umi.com/ku:16752
http://hdl.handle.net/1808/31372
https://orcid.org/0000-0002-6056-3521
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/295612021-03-05T18:33:53Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2019-09-06T20:22:28Z
urn:hdl:1808/29561
The Design and Synthesis of β-Keto Vinyl Sultams and Macrocyclic β-Keto Vinyl Sultams: Novel Analogs of Tetramic Acids
Jha, Jay Shankar
Hanson, Paul R
Rubin, MIchael
Clift, Michael
Organic chemistry
Macrocycle
Reactivity profiling
Tetramic Acids
Vinyl Sultams
Sulfur (S)-containing heterocyclic compounds possessing R1R2N–SO2R3 functionality have been recognized as important due to their innate physical properties that affect biological systems marking them as attractive targets for probing biological pathways. Specifically, sulfonamides and sultams represent two significant compound classes, which exhibit broad ranges of biological activities. Similarly, natural products possessing the tetramic acid core structural motif have emerged as a rich chemotype due to their potent and broad biological activities. Several bioactive tetramic acid-containing compounds have been reported with a variety of activities, including antibacterial, anticancer and anti-inflammatory activities, as well as unique biological profiles in different cell assays. Tetramic acid analogs are also known to modulate protein-protein interactions. In light of the biological significance of the tetramic acid subunit, and the notable physical properties of sulfur containing compounds, we have become interested in the generation of S-analogs of tetramic acids in order to screen for biological activity, and to serve as new probes in Chemical Biology studies with our collaborators. One such class is β-keto sultams, and their unsaturated analogs, both of which represent relatively unexplored chemical space. While there are several reports in the literature for the synthesis of tetramic acid-containing compounds, there are a relatively limited number of examples of the corresponding β-keto sultam analogs. Moreover, their unsaturated analogs are even more limited. It is the purpose of this thesis to start our investigations to explore the substitution of the β-keto sultam group for the iv β-keto lactam subunit in drug-like tetramic acid-containing molecules, which ultimately has the potential to modulate biological activity as well as ADME profiles of the resulting analogs compounds. This thesis will describe the design and synthesis of β-keto sultam analogs of tetramic acids and their corresponding unsaturated and macrocyclic derivatives as novel electrophilic probes that can be modulated electronically, sterically, and stereochemically
2019-09-06T20:22:28Z
2019-09-06T20:22:28Z
2018-08-31
2018
Thesis
http://dissertations.umi.com/ku:16159
http://hdl.handle.net/1808/29561
https://orcid.org/0000-0002-3769-1226
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/87922020-08-25T14:03:04Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2013-06-06T12:10:03Z
urn:hdl:1808/8792
Neurochemical Measurements in Rodents that Model Huntingtion's Disease and Oxidative Stress
Ortiz, Andrea Naomi
Johnson, Michael A
Orr, James A
Lunte, Susan M.
Givens, Richard S
Desaire, Heather
Chemistry
Huntington's disease (HD) is a fatal, neurodegenerative movement disorder caused by a CAG repeat expansion on the gene encoding the huntinin protein. HD is characterized by preferential and extensive striatal degeneration. We used fast-scan cyclic voltammetry to measure dopamine release and reserve pool dopamine in genetically and chemically altered rodents that model HD. Genetic HD model mice and rats (R6/1 mice, R/2 mice, and HDtg rats) showed an age-dependent decrease in dopamine release in the dorsolateral caudate putamen. A similar decrease is not seen in 3-nitropropionic (3NP)-treated rats. In the case of R6/2 mice, stimulation at increasing frequencies showed a decrease in dopamine at the highest frequencies of 50 Hz and 60 Hz. The number of reserve pool vesicles was found to decrease in the R6/2 mice while it increased in the 3NP treated rats. In a separate study, methionine sulfoxide reductase A (MsrA) mice, which model oxidative stress, have been reported to have chronically high dopamine levels relative to control mice. Additionally, these high levels parallel an increased presynaptic dopamine release when stimulated in vitro without drug treatments. Here we show evidence in striatal tissue for an increase in dopaminergic reserve pools that correlates to the increased dopamine levels of this knockout mouse. The results suggest that dopamine in reserve pool vesicles accumulates in the MrsA knockout mouse. This evidence supports previous reports that suggest the amount of dopamine in reserve pools is dependent on the overall dopamine levels, including readily releasable dopamine vesicles.
2012-03-02T19:15:23Z
2013-06-06T12:10:03Z
2011-05-31
2011
Dissertation
http://dissertations.umi.com/ku:11738
http://hdl.handle.net/1808/8792
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/264082018-05-05T08:01:41Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-05-04T15:47:30Z
urn:hdl:1808/26408
The determination of superoxide oxygen and the attempted preparation of lithium and alkaline earth metal superoxides
Seyb, Edgar J.
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1950.
2018-05-04T15:47:30Z
2018-05-04T15:47:30Z
1950
Dissertation
http://hdl.handle.net/1808/26408
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/271642018-11-07T21:31:00Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-11-02T14:18:39Z
urn:hdl:1808/27164
The reaction of sodium azide with ethylene sulfides, ethylenimines and trimethylene oxide
Alsup, Richard Glenn
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1952.
2018-11-02T14:18:39Z
2018-11-02T14:18:39Z
1952
Dissertation
http://hdl.handle.net/1808/27164
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/195892018-12-04T17:22:23Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2016-01-04T02:14:42Z
urn:hdl:1808/19589
DEVELOPMENT OF MICROCHIP ELECTROPHORESIS BASED METHODS TO PROFILE CELLULAR NITROSATIVE STRESS
Gunasekara, Dulan B.
Lunte, Susan M.
Lunte, Craig E.
Berrie, Cindy L.
Givens, Richard S.
Dhar, Prajna
Analytical chemistry
Chemistry
cell analysis
electrochemical detection
laser induced fluorescence detection
microchip electrophoresis
nitric oxide
nitrosative stress
Nitric oxide (NO) is the main reactive nitrogen species (RNS) produced by immune cells. NO reacts with superoxide to produce peroxynitrite (ONOO-). These two RNS are capable of nitration, nitrosylation and oxidation of intracellular biomolecules that can alter various biochemical processes. To help maintain cellular redox homeostasis in nitrosative and oxidative stress, antioxidant molecules are present in the cells. However, excessive nitrosative stress can alter the balance between antioxidants and prooxidants and therefore it plays an important role in cancer, cardiovascular and neurodegenerative diseases. A method for the simultaneous detection of prooxidants and antioxidants associated with nitrosative stress in biological samples would be beneficial for better understanding of their role in disease states. Therefore, in this dissertation a separation-based approach is described that makes it possible to detect and quantify cellular antioxidants and prooxidants such as NO, ONOO-, glutathione and ascorbic acid. Microchip electrophoresis (ME) was selected as the separation method due to its fast analysis times, compatibility with low sample volumes and potential future application to chemical cytometry. Most prooxidants and antioxidants are electrochemically active and therefore, electrochemical detection was used as the primary detection mode. First, a ME method with in-channel amperometric detection that employed an isolated potentiostat was developed for the detection of NO, ONOO-, and other biologically important molecules associated nitrosative stress. Separation of these species was achieved in less than 35 s, which made it possible to detect prooxidants before they significantly degraded. Following this, two dual electrode configurations were developed and evaluated for better identification of reactive species in standard mixtures and cell lysates using voltammetric characterization. The ME-amperometric method was then used for detection and quantification of NO2- and NO in macrophage cells under native and LPS stimulated conditions. Glutathione, a cellular antioxidant, was also measured in these studies and compared with the prooxidant levels in the cells. For further confirmation of NO production in these cells, ME with laser induced fluorescence detection was used for the determination of NO using diaminofluorofluorescein. This same probe and separation was also used to investigate the heterogeneity of NO production in single cells using a cytometric device in collaboration with the Culbertson group. The main future goal of this project is to monitor macrophage cellular heterogeneity during nitrosative stress using an electrochemical cytometric device.
2016-01-04T02:14:42Z
2016-01-04T02:14:42Z
2014-08-31
2014
Dissertation
http://dissertations.umi.com/ku:13573
http://hdl.handle.net/1808/19589
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/278272020-07-09T20:27:17Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2019-05-10T15:42:59Z
urn:hdl:1808/27827
Synthesis of Cyclopropane-Fused 1,5-Diazocin-2-ones via Metal-Templated Intramolecular Addition of Nitrogen Nucleophiles to Pre-Generated Cyclopropenes
Matheny, Jonathon Paul
Rubin, Michael
Rubin, Michael
Hanson, Paul
Tunge, Jon
Organic chemistry
azalactam
cyclization
cyclopropane
cyclopropene
diazocinone
medium-sized heterocycle
This thesis is concerned with the development of methods by which to access compounds possessing the 3,4-cyclopropane-annulated 1,5-diazocin-2-one scaffold. The methods described herein are based on the intramolecular nucleophilic addition of nitrogen nucleophiles to the cyclopropene double bond in a direct 8-membered cyclization. This method allows for access to previously-unknown diazocines of their type – namely, 1,5-diazocin-2-ones possessing fusion to a cyclopropane moiety. The described method allows for potential diversification of the cyclic products via a modular approach to the linear precursors which affords the possibility to easily explore new chemical space by the variation of simple building blocks. Chapter one provides a review of the known methods by which to synthesize 1,5-diazocin-2-ones. The chapter begins by highlighting the importance of members of this class of molecules as effective pharmaceutical agents and as drug candidates. Synthetic methods involving the direct 8-membered cyclization of linear precursors are then discussed – as well as their modes of activation. Furthermore, synthetic approaches to the scaffold by cycloaddition, transition metal-catalyzed tandem reactions, multicomponent reactions, and various rearrangements and fragmentations are discussed. Chapter two describes the development of a synthetic pathway to the direct precursors to the cyclopropane-annulated 1,5-diazocin-2-one scaffolds that are the targets of the efforts of this project. Synthetic strategies are developed and improved upon in order to afford substrates that are relatively easy to construct and assemble in a modular fashion so as to provide easy access to a plethora of new compounds having potentially interesting bioactivities. Chapter three focuses on the strain release-driven cyclizations of the previously described precursors to afford the diazocinone scaffold of interest. The optimization of the reaction and tolerance of the method to the electronic nature of the various nucleophiles employed is discussed. This method is one requiring mild conditions by taking advantage of the high energy and electrophilicity of the cyclopropene moiety. Several novel diazocines are synthesized with the developed method.
2019-05-10T15:42:59Z
2019-05-10T15:42:59Z
2018-08-31
2018
Thesis
http://dissertations.umi.com/ku:16071
http://hdl.handle.net/1808/27827
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/262572018-03-29T08:01:56Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-03-28T15:17:54Z
urn:hdl:1808/26257
Studies on nicotinamide
Bradlow, H. Leon
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1949.
2018-03-28T15:17:54Z
2018-03-28T15:17:54Z
1949
Dissertation
http://hdl.handle.net/1808/26257
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/182232020-06-24T19:22:14Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-07-11T03:53:56Z
urn:hdl:1808/18223
The action of certain formamidines on the pyrazolons
O'Brien, Henry Rust
Thesis (M.A.)--University of Kansas, Chemistry, 1915. Henry Rust O'Brien (1891-1970); Includes bibliographical references.
2015-07-11T03:53:56Z
2015-07-11T03:53:56Z
1915
Thesis
http://hdl.handle.net/1808/18223
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/82602020-08-25T13:51:16Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2011-10-18T21:21:14Z
urn:hdl:1808/8260
Experiments Upon the Explosions of Hydrocarbon Mixtures
Stone, Fred
2011-10-18T21:21:14Z
2011-10-18T21:21:14Z
1904
Thesis
http://hdl.handle.net/1808/8260
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kasas
oai:kuscholarworks.ku.edu:1808/142182020-09-25T14:59:11Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2014-06-18T04:58:33Z
urn:hdl:1808/14218
Nanoscale Manipulation of Surfaces and Interfaces: Engineering Electrical Properties Through Nanofabrication
Smith, Gregory J.
Berrie, Cindy L
Johnson, Carey K
Dunn, Robert C
Jackson, Timothy A
Stagg-Williams, Susan M
Physical chemistry
Nanoscience
Nanotechnology
Atomic force microscopy
Graphite
Kelvin probe force microscopy
Metallic nanowire
Nanofabrication
Nanolithography
Nanotechnology interest and research has increased dramatically over the last decade, but there remain fundamental limitations and barriers to the fabrication of ever smaller devices. To overcome these limitations, new nanofabrication methods and novel nanoscale systems must be explored. To form nanoscale systems, we must have the ability to electrically interconnect various nanoscale parts. To do that, methods must be developed to form nanowires and nanofeatures in a very controlled fashion with arbitrary shapes. It should be noted, however, that materials' properties can change at nanoscale sizes, so these nanowires and nanofeatures themselves must be studied to ensure they function as designed. Materials with unique electronic properties and low dimensionalities, like graphene and carbon nanotubes also need to be studied for potential use in nanoscale devices. Graphene has been found to be electronically tunable by doping, causing it to be able to function as a semiconductor or as a metallic conductor. Understanding this doping interaction will help in the design and implementation of novel nanoscale systems and devices. The first part of this work puts forth a method for fabricating metallic nanofeatures into self-assembled monolayer resists. An atomic force microscope (AFM) is used with methods called nanoetching and grafting and oxidative lithography to form patterned nanofeatures down to 20 nm in width. Nanoetching and grafting involve using the AFM tip to directly remove molecules and replace them with new ones, creating a nanopattern. Oxidative lithography uses a conductive AFM tip as a tiny electrode to write nanopatterns into surfaces by very localized electrochemical oxidation. These nanopatterns are then exposed to an electroless copper plating solution, which selectively plates copper right onto those nanopatterns, to form copper nanofeatures. These are characterized with the AFM that helped form them. With this AFM based method, features of any shape can potentially be formed, providing a way to wire up more complex nanodevices and circuitry. The second part investigates the interaction between graphene-like materials and adsorbates. These interactions are becoming increasingly important as these materials become incorporated into more devices. There has been much study recently focused on graphene and graphene-like materials, such as carbon nanotubes and graphite. Graphene is of particular interest because of its low dimensionality, being a two-dimensional sheet of sp2 hybridized carbon atoms, and its unique properties. It is tough and flexible, but what is most interesting is that its electronic properties are very tunable. Adsorbates can dope it p-type or n-type, so it behaves more like a semiconductor or a metal, respectively. In this work, azulene derivatives and gold nanoparticles are studied as potential adsorbates on graphene-like materials. Azulene molecules themselves have very tunable HOMO and LUMO levels, and it could be possible to dope graphite-like materials in different fashions with different types of azulenes. Gold nanoparticles can also be tunable with size and shape, and their ability to dope graphene-like materials is of interest. Using an AFM technique called surface potential mapping, the electrostatic potential of azulenes adsorbed onto graphite was studied. It was found that azulene and azulene compounds with electron withdrawing groups at the 1 and 3 positions were more negative in the potential than the graphite, indicating they were pulling electrons out of the material. An azulene compound with electron donating groups at the 1 and 3 positions was positive in potential with respect to the graphite surface, indicating donation of electrons to the graphite. This is good evidence that azulenes can be tunable dopants for modifying the properties of graphene-like materials. Using AFM based techniques, this work advances methods to form and electrically characterize nanoscale metallic features and decorated graphene-like materials that could have important applications as nanotechnology moves forward into complex nanodevice fabrication. It also gives insight into a novel system, azulenes on a graphene-like material, at a nanoscale level of resolution. Study of nanosystems like these is integral to the advancement of nanotechnology as a whole.
2014-06-18T04:58:33Z
2014-06-18T04:58:33Z
2013-05-31
2013
Dissertation
http://dissertations.umi.com/ku:12596
http://hdl.handle.net/1808/14218
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/190972017-12-08T21:34:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-12-04T15:09:31Z
urn:hdl:1808/19097
Halogen derivatives of certain azo dyes
Johnson, Carl L.
Project (B.S.)--University of Kansas, Chemistry, 1917. ; Includes bibliographic references.
2015-12-04T15:09:31Z
2015-12-04T15:09:31Z
1917
Thesis
http://hdl.handle.net/1808/19097
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/207662017-12-08T21:40:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2016-05-12T17:08:15Z
urn:hdl:1808/20766
Determination of the ratio of the inert elements in natural gases
Cady, George Hamilton
Thesis (M.A.)--University of Kansas, Chemistry, 1928.
2016-05-12T17:08:15Z
2016-05-12T17:08:15Z
1928
Thesis
http://hdl.handle.net/1808/20766
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/307062021-09-15T19:47:45Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-09-01T20:04:36Z
urn:hdl:1808/30706
Studies on the higher oxides of the alkali and alkaline earth metals
Schechter, William Howard
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1948.
2020-09-01T20:04:36Z
2020-09-01T20:04:36Z
1948-08-31
Dissertation
http://hdl.handle.net/1808/30706
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/207582021-08-26T20:36:19Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-05-03T17:00:30Z
urn:hdl:1808/20758
Hydrogen ion studies in some phosphate solutions
Gottlieb, Selma
Thesis (M.A.)--University of Kansas, Chemistry, 1923.
2016-05-03T17:00:30Z
2016-05-03T17:00:30Z
1923
Thesis
http://hdl.handle.net/1808/20758
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/52542020-06-18T01:18:36Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2009-06-18T20:25:07Z
urn:hdl:1808/5254
Optimization and Applications of Fluorescence anisotropy assays and Fluorescence Resonance Energy Transfer Measurements
Liyanage, Mangala Roshan
Johnson, Carey K
Dunn, Robert C.
Lunte, Susan M.
Berrie, Cindy L.
Middaugh, Russell
Analytical chemistry
Biophysics
Calcium signaling
Calmodulin
Competitive assays
Fluorescence anisotropy
Fret
Pmca
Calmodulin (CaM) is a calcium signaling protein that activates over hundred of targets including PMCA. This dissertation mainly focuses on optimizing and applications of fluorescence anisotropy (FA) and FRET experiments for CaM-target interactions. First we evaluated the extent of interaction of fluorophores with CaM upon conjugation. In this study, three dyes were tested for influences of their charges on interaction with CaM. We employed time-resolved and steady state fluoresce anisotropy as well as fluorescence quenching experiments to study these interactions. The positively charged dye turns out to strongly interact with CaM than neutral and negatively charged dyes. Secondly, FA based assays for direct determination of affinities of CaM-target interactions are developed and the results are consistent with previously reported values. Finally, a FRET based methods are used to study the mechanism of activation of PMCA by CaM and found that the results are consistent with previously reported three-state model.
2009-06-18T20:25:07Z
2009-06-18T20:25:07Z
2009-01-01
2009
Dissertation
http://dissertations.umi.com/ku:10327
http://hdl.handle.net/1808/5254
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/262792018-03-31T08:01:28Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-03-30T17:02:27Z
urn:hdl:1808/26279
A. The mercuration of diphenyl ether and some of its derivatives.B. Derivatives of sulfanilamide
Schroeder, Wesley Dean
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1941.
2018-03-30T17:02:27Z
2018-03-30T17:02:27Z
1941
Dissertation
http://hdl.handle.net/1808/26279
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/185822017-12-08T21:34:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-10-06T18:33:18Z
urn:hdl:1808/18582
The preparation and reactions of some imidazoles
Thompson, Daisy Ruth
Thesis (M.A.)--University of Kansas, Chemistry, 1920. ; Includes bibliographical references.
2015-10-06T18:33:18Z
2015-10-06T18:33:18Z
1920
Thesis
http://hdl.handle.net/1808/18582
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/196232020-10-09T13:36:09Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2016-01-04T03:25:17Z
urn:hdl:1808/19623
New Chemistry of Mercaptoazulenes and Low-Valent Complexes of Isocyanoarenes
Scheetz, Kolbe Joseph
Barybin, Mikhail V
Benson, David R
Jackson, Timothy A
Malinakova, Helena C
Wu, Judy Z
Inorganic chemistry
Aryl mercaptans and their coordination complexes contribute to a number of diverse applications including pharmaceutical, surface science, and molecular electronics, and light emitting diodes. Recently the Barybin group has begun to explore the coordination chemistry of mercaptoazulenes. Prior to the work done by Barybin et al. there were no examples of coordination complexes of featuring mercaptoazulenes. Other mercaptoarenes have been utilized in the formation of thin films and featured in materials with luminescent capabilities. Thiolates have also been studied as junction groups used to attach organic compounds with extended π systems to electrodes. Linear asymmetric dimercaptoarenes are rare, but are intriguing for electronics and construction of molecular electronic components such as diodes. In this dissertation coordination chemistry of mercaptoazulenes, synthesis of azulenic derivatives to probe the charge transport dynamics of the asymmetric 2,6-molecular axis of azulene, and the coordination of isocyanoarenes with low valent transition metal complexes will be discussed. Chapter 1 of the thesis describes the synthesis of the first example of a dimercaptoazulene. Two different synthetic routes were developed for the preparation of this dimercaptan and regioselective metallation was demonstrated for the generation of its mono-nuclear coordination complex. Additionally metallation of the second thiolate termini is also discussed. Chapter 2 describes the synthesis of isomeric mercaptazulenes featuring cyano substituents. The 6-cyano-2-mecaptoazulene has been prepared. These isomeric molecules offer an opportunity to probe the charge transport dynamics of the asymmetric 2,6-molecular axis of azulene. The cyano substituent could serve as a spectroscopic reporter for additional spectroscopic characterization of these molecules in surface studies. Chapter 3 describes the coordination studies of iscyanoarenes with electron rich low valent Mo and W metal centers. This investigation focused on whether substitution variations in non-benzenoid aromatic isocyanides would result in the formation of either cis- or trans- [M(dppe)2(CNAr)2] and related complexes.
2016-01-04T03:25:17Z
2016-01-04T03:25:17Z
2013-08-31
2013
Dissertation
http://dissertations.umi.com/ku:13001
http://hdl.handle.net/1808/19623
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/307112020-09-02T08:01:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-09-01T21:10:13Z
urn:hdl:1808/30711
A study of the reaction between sodium peroxide and oxygen: The preparation and properties of sodium superoxide
Stephanou, Stephen E.
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1949.
2020-09-01T21:10:13Z
2020-09-01T21:10:13Z
1949-05-31
Dissertation
http://hdl.handle.net/1808/30711
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/40262020-07-15T13:21:52Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2008-08-05T02:59:04Z
urn:hdl:1808/4026
Synthesis and Characterization of Polyamine Bicycles for Anion Binding
Morehouse, Paula Kay
Bowman-James, Kristin
Barybin, Mikhail V.
Carlson, Robert G.
Heppert, Joesph
Stagg-Williams, Susan
Inorganic chemistry
Supramolecular
Abstract This thesis details the interaction between anions, such as Br-, Cl-, and F- and a group of familiar Schiff base derived azacryptands. Often these systems are synthesized by tosylating i.e., protecting, the bridging amine sites to prevent them from undesirable interactions. Only after detosylation to retrieve the secondary amines are the anion binding properties investigated. Through our research, we have discovered that when protected (tosylated), the m-xylyl azacryptand [1,4,12,15,18,26,31,39-octaazapentacyclo [13.13.13.1.6,101.20,241.33,37] tetratetraconta-6, 7,9,20(43), 21,23,33(42),34,36-nonaene], N(CH2CH2NHCH2-m-xylyl-CH2NHCH2CH2)3N), 12, is readily capable of being protonated at the bridgehead amines. As a result it is also capable of binding anions. Results from these studies are presented, including the binding of the Brˉ ion, and the crystallographic findings for both the bromide and neutral tosylated azacryptand receptor. Two species were isolated: the neutral cryptand and the dibromide salt. Binding studies and crystal structures are discussed within. Structural aspects of the binding of halides in the p-xylyl octaaza cryptand [1,4,11,14,17,24,29,36-octa-azapentacyclo [12.12.12.26,9.219,22.231,34]-tetratetraconta-6 (43), 7,9(44), 19(41), 20,22(42), 31(39), 32,34(40)-nonaene], N(CH2CH2NHCH2-p-xylyl-CH2NHCH2CH23N), 13, were examined. Crystallographic results for two different Fˉ ion complexes indicated cascade-like coordination, with two F- ions inside the tren-based cavity, bridged by a H2O molecule. In two different Cl- structures, a single Cl- ion and a H2O molecule occupied the cavity. Association constants for the anions, determined by NMR titrations in aqueous solution at pH 5, revealed Log K = 3.15(5) and 3.37(3) for F- and Cl-, respectively. Aspects of the binding of halides, the HSO4- ion, and the SO42- ion in the pyridine-based octaaza cryptand [1,4,12,15,18,26,31,39,42,23,44-undecaaza-pentacyclo- [13.13.13.16,10.120,24.233,37]-tetratetraconta-6,7,9,20(43),21,23,33(42),3436-nonaene], N(CH2CH2NHCH2-pyridine-CH2NHCH2CH2)3N), 14, were examined. Crystallographic results for the Br- ion complex indicated cleft binding, with three internal bromides and three external Br- ions. Association constants for the anions determined by NMR titrations in aqueous solution at pH 3.0 (pH 4.0 for F-), revealed Log K = 3.6 (F-), 1.7 (Cl-), 1.0 (Br-), and less than 1.0 (I-). A 1:2 ligand-to-anion binding mode was observed for the SO42- ion, with respective binding constants of log 4.6 and 2.6. Titrations performed in DMSO-d6 determined the binding constant with HSO4- to be log 3.2. Various methods were used to analyze the ligands and to measure ligand-anion interactions, including mass spectroscopy, 1H NMR, 13C NMR, X-ray crystallography, and elemental analysis.
2008-08-05T02:59:04Z
2008-08-05T02:59:04Z
2007-10-09
2007
Dissertation
http://dissertations.umi.com/ku:2218
http://hdl.handle.net/1808/4026
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/84712020-08-27T13:16:35Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2011-11-22T20:35:19Z
urn:hdl:1808/8471
Vinegar: Its Production and Analysis
Moore, Merle M.
2011-11-22T20:35:19Z
2011-11-22T20:35:19Z
1911-09-01
Thesis
http://hdl.handle.net/1808/8471
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/123552020-09-18T13:16:28Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2013-09-30T21:55:24Z
urn:hdl:1808/12355
Synthetic Approaches to Skeletally Diverse Sultams Using Vinyl- and α-Halo Benzenesulfonamides
Jeon, Kyu Ok
Hanson, Paul R.
Givens, Richard S
Aube, Jeffrey
Tunge, Jon A
Mure, Minae
Chemistry
The development of new chemical methods to generate novel and diverse structures to probe chemical space is an important aspect of early phase drug discovery. Diversity-Oriented Synthesis (DOS) is a powerful strategy that seeks to generate chemical methods capable of delivering an array of molecular scaffolds with structural and functional diversity. Ultimately, these methods can be adapted to produce molecular libraries. It is the purpose of this thesis to highlight a series of new chemical methods that deliver an array of drug-like sultam scaffolds to be screened for broad biological activity in the molecular library program run by the National Institutes of Health. The first project described in chapter one of this dissertation includes the synthesis of a collection of diverse bi- and tricyclic sultams in an overall DOS approach utilizing a ring-opening metathesis / ring-closing metathesis / cross metathesis (ROM-RCM-CM) cascade strategy. A variety of functionalized, tricyclic sultams were generated as precursors derived from a diastereoselective IMDA reaction in good yields and selectivity. The ROM-RCM-CM strategy to produce skeletal and appendage-based diverse sultams is presented. The second project is the generation of diverse sultams utilizing α,β-unsaturated 5- and 6-membered sultams. These 5- and 6-membered sultams were prepared and applied to further diversifications using aza-Michael reactions, cycloadditions, alkylation/benzylations and propargylation-[3+2]-cycloadditions. Utilizing the aza-Michael reaction, we have developed an efficient protocol for the synthesis of a 141-member library collection of isothiazolidine 1,1-dioxide derivatives. The last project outlined in chapter four is the synthesis of novel 7- and 8- membered tricyclic, biaryl sultams using an intramolecular Pd-catalyzed C-arylation reaction. Namely, in the amino ester-derived sultams, remote 1,5- and 1,6-asymmetric induction emanating from the external stereogenic center is operative, whereby a favorable Cα-H/S=O syn pentane interaction, is the source of asymmetric induction for a highly atropdiastereoselective thermodynamic equilibration process yielding a low energy conformer of "like" configuration (S,Sa). In the course of X-ray crystallographic analysis, as well as detailed NMR studies, we uncovered a number of notable and interesting structural features of the 7-membered amino ester-derived sultams in both solid and solution phases that confirm a structure as a single conformer (95:5) containing biaryl axial chirality of "like" configuration (S,Sa) with respect to the stereogenic center in the external side chain. Moreover, variable temperature NMR analysis has indicated that the axis of chirality at the biaryl bond has a relatively small interconversion barrier that allows for this rapid thermodynamic equilibration of the "like" and "unlike" atropdiastereomers. Detailed variable NMR analyses on a number of analogs, vide infra, point to rotamer dynamics (about the N-C bond in the external side chain) and ring size of the corresponding benzothiazepine (n = 1)/benzothiazocine (n = 2) 1,1-dioxides as governing factors in this notable thermodynamic equilibration of atropdiastereomers. Current efforts are focused on the computational calculation for the energy barrier between two atropdiastereomers interconversion, as well as the further development of an "atropdiastereoselective" C-arylation process. In addition, future studies will continue to probe the dynamic factors involved in the origins of atropselectivity. Utilizing this methodology, we are also generating additional libraries of diverse tricyclic, biaryl sultams for high throughput screening of biological activity with our collaborators at the National Institutes of Health.
2013-09-30T21:55:24Z
2013-09-30T21:55:24Z
2012-08-31
2012
Dissertation
http://dissertations.umi.com/ku:12374
http://hdl.handle.net/1808/12355
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/292992020-07-09T20:54:21Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2019-06-12T02:30:21Z
urn:hdl:1808/29299
Synthesis and Characterization of Antigen-Containing Bioconjugates Used to Probe and Modulate Autoimmunity
Leon, Martin Antonio
Berkland, Cory J.
Berkland, Cory J.
Tunge, Jon
Rubin, Michael
Blakemore, James D
Hageman, Michael
Chemistry
Pharmaceutical sciences
Analytical
Autoimmunity
Bioconjugates
Synthetic
Theraputics
Type 1 diabetes
Autoimmune diseases afflict a significant part of the world population and current treatments only treat symptoms or delay the progression of the disease. In the first chapter of this dissertation, an introduction into autoimmunity and current clinically available non-antigen-specific treatments was presented, along with an overview of the rise of antigen-specific immunotherapies (ASIT) as an improved strategy for the treatment of autoimmune diseases. Furthermore, a detailed background into the chemistry utilized in this work to construct novel antigen-specific probes as potential therapies for autoimmune disorders was also offered. A novel class of bioconjugates known as antigen-drug conjugates (AgDCs) have been developed in our group. AgDCs utilize a similar directing strategy as antibody-drug conjugates (ADCs), which use a protein or peptide autoantigen (vehicle) to direct a conjugated drug (payload) to antigen-specific immune cells. Thus, AgDCs are a novel ASIT that may be used to treat autoimmune disorders. Chapter 2 is focused on the synthesis of various chemical biology tools, and the synthetic optimization of ‘clicking’ a modified-mimotope or a synthetic epitope to a potent drug via copper-catalyzed cycloaddition (CuAAC). This work also explored another potential novel therapeutic known as Soluble Antigen Arrays (SAgAs) developed in our group. SAgAs are constructed by using a hydrophilic linear polymer, hyaluronic acid (HA), grafted with multiple repeating autoantigen. SAgA technology introduced tolerance and suppressed disease in several studies in the mouse model of Multiple Sclerosis. SAgAs were also designed for flexibility in accommodating other autoantigens and for facilitating screening of antigen valency effects. Two new type of SAgAs were constructed and characterized using different Type 1 Diabetes autoantigens, namely p79 (chapter 3) and human insulin (chapter 4). Both cSAgAp79 and SAgAIns were tested in vitro to determine if the SAgAs are able to modulate immunological systems.
2019-06-12T02:30:21Z
2019-06-12T02:30:21Z
2018-12-31
2018
Dissertation
http://dissertations.umi.com/ku:16291
http://hdl.handle.net/1808/29299
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/247162017-12-08T21:46:53Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-07-07T21:10:02Z
urn:hdl:1808/24716
Hybrid antimalarials; the reaction of 8-amino-quinolines with nitrodiols
Donahoe, Hugh B.
VanderWerf, Calvin A.
Reynolds, Charles A.
Burckhalter, J. H.
Thesis (Ph. D.)--University of Kansas, Chemistry, 1950.
Malaria is one of the oldest diseases known to man, and, even today, with the great advances in medical science, it affects a large percentage of the human race. It has been estimated that.the disease attacks several hundred million people every year and that it accounts for three million.fatalities in the same period of time. Approximately twenty•five per cent of the hospital
admissions among United States troops stationed at Vera Cruz in the Mexican war was due to malaria and there were 1,213,685 cases among the white troops on the Union side during the Civil War. The disease prevented action by both Allied and Central Powers in the Near East in World War I, and it has been reported that the incidence of malaria in the Pacific reached 750 per thousand per annum in the early years of the Second World War. In the United
States, which is in a temperate zone, an estimated one million persons are infected and it has been found in every
state in the Union. A never-ending search for more potent and less toxic antimalarials has continued and will undoubtedly do
so until this scourge is no longer of importance.
2017-07-07T21:10:02Z
2017-07-07T21:10:02Z
1950-05
Dissertation
http://hdl.handle.net/1808/24716
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/223832018-01-31T20:07:48Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-01-03T04:09:55Z
urn:hdl:1808/22383
Conformational Analysis of Intrinsically Disordered Proteins Using Mass Spectrometry-Based Approaches
Al-Naqshabandi, Mohammed Ali Hussain
Weis, David D.
Berrie, Cindy L.
De Guzman, Roberto
Johnson, Carey K.
Wang, Michael
Chemistry
Analytical chemistry
Biochemistry
fast photochemical oxidation of proteins
Hydrogen exchange mass spectrometry
Intrinsically disordered proteins
Mass Spectrometry
Intrinsically disordered proteins (IDPs) have regions that are highly flexible and lack stable secondary or tertiary structure. Recently, there has been a growing interest in IDPs due to their important roles in many biological processes and functions. Although many studies have shown that IDPs participate in functional interactions, less is known about the structural details of the interactions. Over the past two decades, mass spectrometry (MS) has become a powerful technique for biophysical characterization of proteins due to its high sensitivity and variety of choices for sample preparation and instrumentation. Here I present the application of two important mass spectrometry-based approaches: hydrogen exchange (HX) and fast photochemical oxidation of proteins (FPOP) to study disordered proteins. HX-MS was applied to better understand the mechanism of calcineurin activation. Calcineurin is a heterodimeric phosphatase that plays essential roles in cellular processes. Previous work has established that at high calcium concentration, calmodulin binds calcium ions, resulting in calmodulin binding to the intrinsically disordered regulatory domain of calcineurin. Calmodulin binding causes release of the autoinhibitory domain from the active site, activating calcineurin. My results with full-length calcineurin demonstrate that the regulatory domain is unstructured in the absence of calmodulin, while it folds upon binding to calmodulin. This result confirms previous work on the isolated regulatory-autoinhibitory domain construct. Additionally, I have observed calmodulin-induced changes in peptides located in other domains of calcineurin. Finally, and surprisingly, I found no changes in the structuring of the calcineurin autoinhibitory domain upon calmodulin binding. I present results from all regions of the calcineurin to describe the mechanism of calcineurin activation. I also propose a new model of calcineurin activation upon calmodulin binding. The degree of structure measurement in IDPs can provide important information about the mechanisms by which IDPs undergo coupled folding and binding. Different approaches to quantify the degree of structure in IDPs using millisecond HX were explored. A quench-flow device, built in-house, for HX labeling on the millisecond timescale was employed. It is essentially impossible to determine the degree of structure without having an accurate unprotected reference state. The interaction domains of the activator for thyroid and retinoid receptors (ACTR) and the CREB binding protein (CBP) were used as model IDPs to explore the best approach to produce an unprotected reference state for millisecond HX. ACTR is a near-random coil IDP that has some residual helicity while CBP is a molten globular IDP that transiently becomes unstructured as revealed by NMR and HX-MS. The approaches explored to obtain an unprotected reference state in HX experiments were chemical exchange calculations, addition of denaturing agents, and millisecond HX labeling of peptic peptides obtained from the IDP. It was found that peptic reference peptides can be used as an accurate unprotected reference state for determining the degree of the structure. Due to its fast labeling timeframe, FPOP might reveal states of IDPs that are undetectable by HX. The application of the FPOP technique for characterizing IDPs was also evaluated. To explore the applicability of this technique for studying IDPs, ACTR and CBP as model systems that co-fold upon binding were used. The FPOP technique was utilized to study ACTR and CBP in their free and bound forms. The data show that FPOP provided useful information to compare two states of IDPs. The usefulness and limitations of FPOP analysis to characterize and localize regions of protein-protein interactions involving IDPs are illustrated.
2017-01-03T04:09:55Z
2017-01-03T04:09:55Z
2016-08-31
2016
Dissertation
http://dissertations.umi.com/ku:14852
http://hdl.handle.net/1808/22383
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/121982020-10-14T13:55:10Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2013-09-29T14:40:24Z
urn:hdl:1808/12198
STRATEGIC COMBINATION OF TRANSITION METAL-CATALYZED REACTIONS FOR ECONOMICAL ONE-POT SYNTHESES OF N-HETEROCYCLES
Raikar, Sandeep
Malinakova, Helena C
Tunge, Jon A
Givens, Richard S
Mure, Minae
Prisinzano, Thomas E.
Organic chemistry
Diversity oriented synthesis
One-pot reactions
Sequential transition metal catalysis
There has been extraordinary progress in the field of chemical synthesis over the last couple of decades. Innovative methodologies and robust catalysts are emerging. Propelled by all these inventions the evolution of the field has reached the state when the principle concern of a synthetic chemist is not whether a molecule can be synthesized, but how rapidly and economically can it be produced. In this regard the development and application of one-pot reactions and multicomponent reactions play a major role because of their excellent overall economy of operation. The goal of this dissertation is to expand our understanding of regiocontrol of known transition metal-catalyzed reactions, and design one-pot protocols towards syntheses of medicinally relevant heterocycles. The first project described in chapter 2 of this dissertation, demonstrates the development of a synthetic method utilizing a Pd-catalyzed multicomponent reaction (MCR) previously developed in our laboratory for synthesis of highly substituted pyrrolidines and tetrahydrofurans. The project also helped us to unequivocally assign the relative stereochemistry of the precursors proposed in our previous reports. Methodology reported herein opens up possible future application towards synthesis of potent ETA antagonist-atrasentan and natural products like kainic acid and acromelic acid. The second project described in chapter 3, illustrates the concept of strategic sequencing of a MCR with transition metal-catalyzed annulation reactions. Herein, Cu-catalyzed MCR of imine, acid chloride and terminal alkyne was used to assemble highly functionalized enynes which upon ring closing enyne metathesis and Heck cyclization delivered N-heterocycles such as benzoindolines, dihydro pyrroloquinolines, cyclopropane fused dihydro indenopyridines and phenanthrolines. Divergence in an unexpected 5-exo vs 6-endo pathway during the Heck cyclization of homologous or isosteric substrates was observed. We believe the substrate conformation and the chelation are the factors which govern the regiodivergent Heck cyclization. A plausible mechanism for this regiodivergent Heck annulation is proposed. The third project described in chapter 4, presents efforts towards the successful design of a sequential one-pot protocol for the enyne metathesis and Heck cyclization illustrated in project two. A sequential one-pot methodology was realized for Ru/Pd catalyzed annulation reactions. Optimization of a common solvent for dual metal catalysis and a suitable base for Pd catalysis proved to be critical. The yields of pure heterocycles obtained via one-pot protocol were 2-22% higher in comparision with the stepwise procedure.
2013-09-29T14:40:24Z
2013-09-29T14:40:24Z
2013-08-31
2013
Dissertation
http://dissertations.umi.com/ku:12973
http://hdl.handle.net/1808/12198
https://orcid.org/0000-0003-0258-4364
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/306592020-08-26T08:01:07Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-08-25T15:07:23Z
urn:hdl:1808/30659
Iodination of hydroxy derivatives of diphenyl ether
Choguill, Harold S.
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1937.
2020-08-25T15:07:23Z
2020-08-25T15:07:23Z
1937-05-31
Dissertation
http://hdl.handle.net/1808/30659
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/184842020-06-24T18:10:18Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-09-21T18:31:03Z
urn:hdl:1808/18484
A zinc-copper couple for the reduction of iron for permanganate titration
Jones, William Albert
Thesis (M.S.)--University of Kansas, Chemistry, 1916. ; Includes bibliographical references.
2015-09-21T18:31:03Z
2015-09-21T18:31:03Z
1916
Thesis
http://hdl.handle.net/1808/18484
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/257522018-06-01T15:47:01Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-01-28T22:35:48Z
urn:hdl:1808/25752
Characterization and Activation of Bioinspired Peroxomanganese(III) Complexes
Colmer, Hannah Elizabeth
Jackson, Timothy A
Barybin, Mikhail V
Thompson, Ward H
Blakemore, James D
Bravo-Suarez, Juan J
Chemistry
Inorganic chemistry
Physical chemistry
Bioinspired
Computational
Intermediate
Manganese
Peroxo
Spectroscopy
Many biochemical reactions critical for life require catalysis by manganese-containing enzymes that react with dioxygen or its reduced forms to generate manganese-oxo, peroxo, or hydroxo intermediates. These reactions are prevalent throughout nature and include the synthesis of DNA by ribonucleotide reductases, free radical detoxification by superoxide dismutases, and metabolic pathways catalyzed by cytochrome P450 enzymes. Peroxomanganese(III) intermediates are proposed in many of the catalytic cycles that are governed by manganese-containing enzymes, and are often precursors to high-valent active oxidant species that are capable of substrate oxidation. While there have been successful synthetic models of the active sites of many enzymes, the factors that direct the reactivity of these peroxomanganese(III) intermediates are not well defined. In particular, the electronic and geometric effects of the supporting ligand system on the reactivity of peroxomanganese(III) species are poorly understood. To characterize the geometric structures and inherent reactivity of these intermediates, low-temperature spectroscopic techniques have been utilized, including electronic absorption, electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), and X-ray absorption spectroscopy (XAS). In addition, these complexes and their reactivity have been computationally explored through density functional theory (DFT), time-dependent DFT (TD-DFT), and multi-reference ab initio computations. A MnIII-peroxo species supported by the neutral, cross-clamped Me2EBC ligand was prepared and spectroscopically and computationally characterized. The reactivity of the [MnIII(O2)(Me2EBC)]+ species with redox-active MnII was explored and found to display unique reactivity compared to other MnIII-peroxo species by generating mononuclear high-valent products and avoiding dinuclear product formation. This reactivity is reminiscent of the catalytic cycle observed in enzymatic systems and is the one of the few examples of activation of a MnIII-peroxo species to mononuclear, high-valent intermediates. Additional reactivity studies of [MnIII(O2)(Me2EBC)]+ were explored, including activation by the addition of protons from Brønsted acids, hydrogen atom addition from electrophilic substrates, and modulation of the electron density of the MnIII-peroxo moiety through Lewis acid addition. A trispyrazolylborate scorpionate-type ligand (TpPh2) was used to support a stable MnIII-peroxo species that was characterized by spectroscopic and computational methods. The [MnIII(O2)(TpPh2)(THF)]+ complex displays a blue-shift in the lowest energy transition compared to other MnIII-peroxo species, and this shift was determined to be a result of an axial bond elongation that stabilized the donor MO in this transition. Perturbations in the electronic structure of this MnIII-peroxo species and two isomers of the related [MnIII(O2)(TpiPr2)(pziPr2H)] species were explored through TD-DFT and multireference ab initio computations. Controlling O—O bond reactivity is a critical step in the modulation of the activation of MnIII-peroxo species, but there are few successful studies in this area. A MnIII-peroxo species supported by a pentadentate, N4O- ligand was electrochemically formed and displayed reductive activation that was controlled by the strength acid added to the reaction. In the presence of a strong acid, Mn—O bond cleavage with generation of H2O2 occurred; but in the presence of a weak acid, O—O bond cleavage was observed. The mechanism of O—O bond activation in MnIII-peroxo species supported by the N4O-, Me2EBC, and TMC ligands was explored by DFT calculations, and the role of the ligand in in the reductive activation process was evaluated. These calculations indicate that a stable supporting framework with a moderate amount of steric bulk is optimal for the reductive activation of MnIII-peroxo species. In addition to characterization and reactivity of MnIII-peroxo species, this work also contributes to the investigation of MnIII complexes with unusual spin states. While most MnIII complex are high-spin (S=2), several low-spin (S=1) MnIII species supported by trispyrazolylborate scorpionate-type ligands (Tp, Tp*) and a related N-heterocyclic carbene ligand were evaluated spectroscopically and computationally. The effect of the ligand in stabilizing these unusual spin states was examined through variable-temperature variable-field MCD spectroscopy and multireference ab initio calculations. While there are few methods available to treat the potentially orbitally-degenerate ground state of these low-spin MnIII complexes, NEVPT2/CASSCF computations were used to successfully reproduce the experimental zero field splitting parameters of these complexes. The results from these studies determined that a shift in the lowest lying triplet state is a result of strong σ-donation from the ligand. In many enzymatic catalytic cycles, metal-peroxo intermediates are precursors to the active metal-oxo species, and these metal-oxo species display high specificity for product distribution in substrate oxidation. While there are synthetic MnIV-oxo model species that display substrate reactivity, it is an ongoing investigation to replicate the controlled specificity present in enzyme systems. Two model complexes, [MnIV(OH)2(Me2EBC)]2+ and [MnIV(O)(OH)(Me2EBC)]+ differ only by one proton and are able to the direct the reaction with DHA to desaturated and hydroxylated products, respectively. To determine the fundamental parameters directing this reactivity, DFT calculations of hydrogen atom transfer, as well as the product formation steps, were performed for both MnIV species with DHA.
2018-01-28T22:35:48Z
2018-01-28T22:35:48Z
2016-05-31
2016
Dissertation
http://dissertations.umi.com/ku:14547
http://hdl.handle.net/1808/25752
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/97732020-07-14T13:15:19Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2012-06-03T15:19:03Z
urn:hdl:1808/9773
Constructivist-Based Asynchronous Tutorial to Improve Transfer between Math and Chemistry Domains: Design, Implementation, and Analysis of the Impact of ReMATCH on General Chemistry Course Performance and Confidence
Barker, M. Danielle
Heppert, Joseph A.
Berrie, Cindy L.
Carlson, Robert G.
Hierl, Peter M.
Frey, Bruce B.
Secondary education
Chemistry
Educational technology
Chemical education
Constructivism
Math
Transfer
Tutorials
The two-year implementation of ReMATCH, a web-based math and problem-solving tutorial, in a traditionally arranged general chemistry classroom at the University of Kansas examined the impact of a designed intervention to assist students with the transfer of their mathematical knowledge to a chemistry context where it could be readily used for quantitative problem solving. The ReMATCH intervention, designed on constructivist-based pedagogies, focused on illuminating the expert-processes of problem solving and transferring knowledge across domains to the novice chemistry. The two implementations of ReMATCH - once as lab assignments and once lecture assignments - resulted in very different student responses to the intervention. However, within both, the beneficial effects of sustained ReMATCH-use were visible. In 2006, students who attempted all of the ReMATCH homework assignments were predicted to earn ~5% higher on their total exam points. The 2007 implementation of ReMATCH demonstrated that students who attempted all of the homework problems and visited at least half of the ReMATCH tutorial pages were predicted to earn ~8.5% higher on their total exam points. Additionally, use of ReMATCH in 2006 also resulted in increased confidence (as measured by comfort-level) with some of the math-related chemistry topics covered in ReMATCH. In 2007, when only students who attempted all of the ReMATCH problems were considered, it became clear that individuals who were initially less confident in their math-related chemistry skills were more likely to view more of the ReMATCH tutorial pages. When students with lower initial comfort-levels on these topics viewed at least half of the ReMATCH tutorial pages, they were able to compensate for their initially lower levels of confidence and were equally comfortable with most of the math-related chemistry topics by the final survey. Student interactions with and perceptions of ReMATCH showed that student attitudes towards ReMATCH could be described by two factors: (1) how relevant and (2) how accessible they found the tutorial and homework to be. Students with more sustained interactions with ReMATCH presented more positive attitudes regarding the accessibility of the website in the 2006 study.
2012-06-03T15:19:03Z
2012-06-03T15:19:03Z
2011-12-31
2011
Dissertation
http://dissertations.umi.com/ku:11904
http://hdl.handle.net/1808/9773
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/306952020-09-01T08:01:31Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-08-31T15:24:57Z
urn:hdl:1808/30695
Thermodynamic properties of some alkali metal peroxides and superoxides, and the dissociation energy of fluorine
Margrave, John Lee
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1950.
2020-08-31T15:24:57Z
2020-08-31T15:24:57Z
1950-12-31
Dissertation
http://hdl.handle.net/1808/30695
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/268872018-10-20T08:03:09Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-10-19T19:14:59Z
urn:hdl:1808/26887
The synthesis of organic medicinals containing fluorine
Helin, Arthur F.
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1950.
2018-10-19T19:14:59Z
2018-10-19T19:14:59Z
1950
Dissertation
http://hdl.handle.net/1808/26887
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/306812020-08-28T08:00:57Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-08-27T14:02:17Z
urn:hdl:1808/30681
Some studies in the transference of ions in anhydrous acetic acid solutions
Holm, Vernon
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1932.
2020-08-27T14:02:17Z
2020-08-27T14:02:17Z
1932-05-31
Dissertation
http://hdl.handle.net/1808/30681
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/239522018-07-23T16:44:57Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-05-07T20:19:41Z
urn:hdl:1808/23952
Methods for Sultam Library Synthesis: One-pot, Sequential Protocols
Asad, Naeem
Hanson, Paul R
Hanson, Paul R
Aubé, Jeffrey
Givens, Richard S
Rubin, Michael
Malinakova, Helena
Chemistry
Organic chemistry
Biology
Acyl sultams
One-pot
One-pot Sequential
Ring opening metathesis polymerization
Sultams
thiadiazepin- 1(2H)-one 3
3-dioxides
The focus of this dissertation is to utilize vinyl sulfonamides in a series of reaction protocols towards the synthesis of sultam molecules by exploiting several salient features inherent to sulfonamides, including (i) electrophilicity of the β-carbon for Michael addition, (ii) low pKa suitable for alkylation, (iii) exploitation of the double bond for Heck, Diels-Alder and metathesis reactions. Overall, vinyl sulfonamides undergo several selective transformations to allow access to diverse sultams, which can be further utilized in library synthesis. Chapter one outlines the biological activity of sulfonamides and sultams and ends with a mini-review on the use of vinyl sulfonamides for sultam synthesis. Chapter two begins with a brief review of the bioactivity of acyl sulfonamides and acyl sultams, and then details a one-pot, sequential protocol employing complementary ambiphile (an entity having a nucleophilic and an electrophilic center) pairing (CAP) of vinyl sulfonamides with a variety of unprotected amino acids via aza-Michael addition followed by intramolecular EDC coupling (amidation). Utilizing this methodology diverse, sp3-rich mono- and bicyclic acyl sultams were synthesized in a highly scalable manner. In addition, stereochemically-rich building blocks were constructed and a method was developed to provide quick access to all possible isomers. This method was also further extended to include one-pot, sequential 3-, 4-, and 5-multicomponent protocols. Chapter 3 describes a stereo-controlled diversification of (8R,9aS)-8-hydroxy-2-(prop-2-yn-1-yl)hexahydro-pyrrolo[2,1-d][1,2,5]thiadiazepin-1(2H)-one 3,3-dioxide 3.1.1, utilizing a one-pot, click-OACC esterification protocol and a one-pot, sequential Mitsunobu alkylation pathway. The core (8R,9aS)-8-hydroxy-2-(prop-2-yn-1-yl)hexahydropyrrolo[2,1-d][1,2,5]thia-diazepin-1(2H)-one 3,3-dioxide, was synthesized rapidly on a multi-gram scale by a one-pot, sequential sulfonylation, Michael and EDC/amide coupling protocol. A compound library comprised of 135/158-members was generated utilizing these protocols. Chapter 3 also describes an efficient one-pot, sequential or 4-component protocol to access a library of stereochemically-rich acyl sultams containing varied elements of skeletal and peripheral diversity. The 3-component protocol consisted of sulfonylation of amines with 2-chloroethane sulfonyl chloride, aza-Michael with amino acids and amide coupling, and was extended to a similar 4-component procedure involving the aforementioned reactions followed by the fourth reaction, including: (i) a [3+2] Huisgen cycloaddition when propargyl amine was utilized in the sulfonylation step and (ii) carbamoylation when L-trans-hydroxyproline was employed in the aza-Michael reaction. The construction of two libraries of triazole-containing isothiazolidine 1,1-dioxides utilizing click/OACC esterification protocol is also reported in chapter 3. A core dihydroisothiazole 1,1-dioxide scaffold was prepared rapidly on multi-gram scale via ring-closing metathesis (RCM), followed by propargylation. In this method, an aza-Michael reaction employing three amino alcohols was used to generate three daughter scaffolds. This was followed by a one-pot, click/esterification protocol utilizing an oligomeric coupling reagent (OACC) to generate a 41-member library of triazole-containing isothiazole 1,1-dioxides. Chapter 4 describes the utilization of facilitated, chromatography-free intermolecular Monomer-on-Monomer Mitsunobu protocols on hydroxy-pyrrolo thiadiazepin-dioxide scaffolds. The MoM Mitsunobu reaction was employed by norbornenyl-tagged benzyl ethyl azodicarboxylate (Nb-BEAD) and Nb-tagged triphenylphosphine (Nb-TPP) whereby purification/sequestration of excess and spent reagents was rapidly achieved using ring-opening metathesis (ROM) polymerization. Facile purification was carried-out utilizing surface-initiated polymerization by three sequestration methods: (i) from free metathesis catalyst (G-II) (ii) Nb-tagged silica (Nb-Si) (iii) Nb-tagged Cobalt-graphite (Nb-Co/C) magnetic nanoparticles. Another purification protocol is reported which utilizes a ROMP derived process for the diversification of tricyclic sultams (epoxybenzo[d]isothiazole 1,1-dioxides). This chromatography-free method permits easy isolation of reductive-Heck products and retrieval of excess starting material utilizing a sequestration protocol involving metathesis catalysts and a catalyst-armed Si-surface.
2017-05-07T20:19:41Z
2017-05-07T20:19:41Z
2014-08-31
2014
Dissertation
http://dissertations.umi.com/ku:13629
http://hdl.handle.net/1808/23952
https://orcid.org/0000-0001-6871-5270
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/148292020-10-21T15:24:17Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2014-07-28T02:03:06Z
urn:hdl:1808/14829
Synthesis of Densely Functionalized Cyclopropanes via Diastereoselective Nucleophilic Additions to in Situ Generated Cyclopropenes
Ryabchuk, Pavel
Rubin, Michael
Hanson, Paul
Malinakova, Helena
Barybin, Mikhail
Chaudhari, Raghunath
Chemistry
Aminocyclopropanecarboxylic acid
Aza-michael
Bromocyclopropanes
Cyclopropene
Donor-acceptor cyclopropanes
Oxa-michael
This thesis is concerned with the development and application of methods for the diastereoselective synthesis of substituted cyclopropanes. The methodology described in this dissertation is based on the addition of nucleophiles to highly reactive cyclopropene intermediates, to which a variety of oxygen and nitrogen-based nucleophiles can be efficiently employed in this transformation. The presented methodology provides easy access to di-, tri- and tetrasubstituted cyclopropanes which is divided into three chapters and describes not only the methodology developed in our research group but also other synthetic routes to densely substituted cyclopropanes. Chapter one is a review of synthetic methodologies for the preparation of densely substituted chirally-rich cyclopropanes with three stereocenters. The first part of the chapter will describe the stereoselective addition of zinc carbenoids to substituted alkenes. The following section will cover recent advances in the field of transition-metal-catalyzed carbene chemistry. Other methods including Michael-initiated ring closure and C-H activation reactions will be discussed in the final part of chapter one. Chapter two focuses on intermolecular formal nucleophilic substitution of bromocyclopropanes with azoles and anilines. The developed methodology aims for the construction of stereodefined di- and trisubstituted cyclopropanes. Formal substitution of bromocyclopropanes proceeds via the dehydrohalogenation of bromocyclopropane generating cyclopropene in situ followed by subsequent addition of a nitrogen-based nucleophile with efficient selectivity control achieved by thermodynamically driven epimerization of enolizable carboxamides or directing effect of a substituent on a three-membered cycle. Chapter three describes a highly efficient and diastereoselective synthesis of tetrasubstituted donor-acceptor cyclopropanes that can be obtained in a homochiral form from corresponding bromocyclopropyl carboxylic acids. A single chiral center on bromocyclopropane dictates the configuration of the other two stereocenters that are successively installed via a sterically controlled addition of a nucleophile to a chiral trisubstituted cyclopropene, followed by a thermodynamically driven epimerization of the resulting enolate intermediate. This new "dual-control" strategy was successfully employed to the synthesis of densely substituted cyclopropanes in inter- and intramolecular fashion.
2014-07-28T02:03:06Z
2014-07-28T02:03:06Z
2013-12-31
2013
Dissertation
http://dissertations.umi.com/ku:13124
http://hdl.handle.net/1808/14829
https://orcid.org/0000-0003-2859-3867
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/197202017-12-08T21:31:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-01-06T17:16:22Z
urn:hdl:1808/19720
Direct iodination of organic compounds thru the agency of nitric acid and determination of halogens in organic compounds by the means of liquid ammonia
Nelson, Harley Arthur
Includes bibliographical references.
2016-01-06T17:16:22Z
2016-01-06T17:16:22Z
1917
Thesis
http://hdl.handle.net/1808/19720
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/63882020-08-03T14:12:47Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2010-07-05T22:47:10Z
urn:hdl:1808/6388
Assessment of the Efficacy of Blended Learning in an Introductory Pharmacy Class
Munson, Christina Elizabeth
Heppert, Joseph A.
Carlson, Robert G.
Hanson, Paul R.
Benson, David R.
Skorupski, William
Education
Science
Health education
Health sciences
Pharmacy
Blended learning
Face-to-face
Hybrid learning
Online lectures
Blended learning is the convergence between traditional face-to-face learning typically seen in a university setting and a computer-mediated learning environment, and is increasingly being seen as a viable alternative for learning instruction. Pharmaceutical calculations (PC) is a course taken by students in the first year in the school of pharmacy at the University of Kansas (KU SOP). One of the objectives of the PC class is that students are able to perform calculations with minimal error consistently. This requires repetitive drill which is a poor use of class time. By moving presentation of material online and using class time for small learning group problem solving as well as practice exams, the transformation of the course to a blended or hybrid course is assessed for efficacy and found to have student outcomes which are comparable to previous face-to-face (F2F) classes. As KU SOP expands it class sizes from 105 to ~150 students and its campuses (building a satellite campus in Wichita, Kansas), being able to provide quality instruction at a reasonable cost is desirable. By redesigning PC to be a hybrid course, the need to hire additional instructors and/or increase available resources is minimized. Instructors remain for the large part on the main campus in Lawrence while students are learning at remote locations, a cost-effective measure for all parties involved. Using small learning groups (consisting of not more than 3 or 4 students) to work problems in PC was demonstrated to be an effective use of F2F class time in the fall semester, 2008 at KU. The class was taught by the same instructor in the fall of 2009 using blended learning as the class format. The current computer Learning Management System (LMS) in use at KU is Blackboard(©2010). By using Blackboard to deliver lectures and have students work through tutorials to learn the material, class time was devoted to highly-focused problem solving. Due to unequal data distribution, the non-parametric tests Kruskal-Wallis and Mann-Whitney were used to assess student outcomes from three different classes (years) of students. The only significant differences were between groups of males in two different face-to-face classes. There was no significant difference between BL and F2F class formats. In general, blended learning was found to be as effective as a traditional F2F class format when comparing final student outcomes.
2010-07-05T22:47:10Z
2010-07-05T22:47:10Z
2010-04-26
2010
Dissertation
http://dissertations.umi.com/ku:10767
http://hdl.handle.net/1808/6388
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/103202020-09-10T13:20:12Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2012-10-28T17:09:57Z
urn:hdl:1808/10320
Palladium-catalyzed allylic alkylation via decarboxylative and retro-Claisen C-C cleavage methods
Grenning, Alexander J.
Tunge, Jon A.
Altman, Ryan A.
Aube, Jeffrey
Hanson, Paul R.
Malinakova, Helena C.
Chemistry
Organic chemistry
Allylic alkylation
Decarboxylative coupling
Palladium catalysis
Retro-claisen condensation
Presented herein is the development of new methods for Pd-catalyzed allylic alkylation with a central focus on reactions that generate molecular complexity rapidly with little waste byproduct. With this simply stated, yet challenging goal in mind, we present the decarboxylative allylation (DcA) of nitroalkanes and the conceptually novel deacylative allylation (DaA, or retro-Claisen) reaction. The main unifying themes of this research are (a) Pd-catalyzed allylation, (b) in-situ generation of nucleophilic and electrophilic coupling partners, and (c) "green" synthetic methods. Regarding the former topic, DcA of nitroalkanes, we have developed methods for the synthesis of both tertiary and secondary allylated nitroalkanes using decarboxylation as a strategy. Carbon dioxide is the only byproduct and the organic building blocks prepared by this method are easily converted into nitrogen-containing heterocycles by functional group pairing. The conceptually new deacylative allylation (DaA) reaction has been shown to be a useful method for allylation of various in situ generated nucleophiles. The reaction leads to similar products as can be accessed by the DcA method, but has many added benefits. For example, both nucleophilic and electrophilic coupling partners are prepared in situ by a single retro-Claisen event. Furthermore, DaA substrate synthesis begins from commercial/readily available active methylene nucleophiles (β-dicarbonyl compounds) and can utilize robust methods previously developed for these compounds (e.g. Cu/Pd-catalzyed arylation, Tsuji-Trost allylation, etc.). The DaA reaction itself directly couples allylic alcohols, which is desirable due to their availability and reduced toxicity compared to other allylating agents. In terms of utility, DaA can rapidly construct 1,6-heptadienes (cycloisomerization substrates) via 1-pot 3-component coupling. We have also utilized the reaction to construct an important intermediate ¬en route ¬to the drug verapamil as well an asymmetric DaA reaction that allows formal access to (+)-hamigeran and other enantioenriched tetralone derivatives.
2012-10-28T17:09:57Z
2012-10-28T17:09:57Z
2012-05-31
2012
Dissertation
http://dissertations.umi.com/ku:12035
http://hdl.handle.net/1808/10320
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/40182020-07-16T13:08:14Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2008-08-05T02:39:21Z
urn:hdl:1808/4018
Development of Analytical Methods Coupled to Microdialysis Sampling for Studying Biomarkers of Oxidative Stress
Hoque, Ehsanul
Lunte, Craig E.
Lunte, Susan M.
Rivera, Mario
Dunn, Robert C.
Desaire, Heather
Analytical chemistry
Oxidative stress
Biomarkers
Glutathione
Hydroxyl radicals
Ce
Hplc
This research describes the development of analytical methods based upon separation techniques coupled to microdialysis sampling for the detection of potential biomarkers of oxidative stress. The research focused on two biomarkers, glutathione and the hydroxyl radical (.OH). Microdialysis sampling was utilized for the continuous monitoring of these biomarkers in rat liver and heart. Oxidative stress was induced, causing the generation of reactive oxygen species (ROS). It was hypothesized that ROS generation would increase in biological systems due to induced oxidative stress. In one investigation, a capillary electrophoresis (CE) method with ultra-violet (UV) detection was developed employing pH-mediated stacking, an on-column preconcentration technique, to detect two forms of glutathione, reduced glutathione (GSH) and oxidized glutathione (GSSG), simultaneously in microdialysates. The detection limits necessary for measuring GSH and GSSG in microdialysates with UV detection could not be achieved without the use of pH-mediated stacking. The method was utilized to monitor glutathione in microdialysates from rat liver that was subjected to chemically induced oxidative stress using adriamycin. GSSG concentration was found to increase from the basal concentration as a result of oxidative stress, suggesting increased antioxidant activities during oxidative stress. For the indirect detection of .OH in microdialysates, a trapping agent, 4-hydroxybenzoic acid (4-HBA), was employed. Indirect determination involved the trapping of .OH by 4-HBA and then detection of the radical adduct, 3,4-dihydroxybenzoic acid (3,4-DHBA), by the developed CE-UV method. In vitro studies of .OH generation systems (e.g., UV photolysis of H2O2, the Fenton reaction, and hypoxanthine/xanthine oxidase systems with and without superoxide dismutase) demonstrated the capability of 4-HBA to trap .OH and the ability of the CE-UV method to detect 3,4-DHBA in the reaction products. Finally, an in vivo investigation was performed using CE-UV and high performance liquid chromatography (HPLC) method with electrochemical (EC) detection to detect 3,4-DHBA in microdialysates from rat heart where 4-HBA was delivered through the microdialysis probe to trap .OH. Increased generation of 3,4-DHBA was observed in microdialysates of rat heart subjected to physically induced oxidative stress (ischemia-reperfusion), suggesting increased generation of ROS during oxidative stress.
2008-08-05T02:39:21Z
2008-08-05T02:39:21Z
2007-12-18
2007
Dissertation
http://dissertations.umi.com/ku:2307
http://hdl.handle.net/1808/4018
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/142052020-10-22T14:03:19Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2014-06-18T03:47:36Z
urn:hdl:1808/14205
Model membranes as a tool for biological studies and biosensor applications
Armendariz, Kevin P.
Dunn, Robert C
Lunte, Susan M
Lunte, Craig E
Berrie, Cindy L
Hefty, Scott P
Analytical chemistry
Bioassay
Fluorescence
Membrane
Orientation
Single molecule
Whispering gallery mode
The biological membrane is a fundamental cellular structure which forms the natural selective barrier separating cells from their environment. Model membranes have long been employed to study these complicated structures in controlled environments. Within this dissertation we report the use of a defocused single molecule fluorescence imaging approach for examining the molecular level structure of model membranes which incorporate biological lipid components. Through these single molecule studies, an optimal single molecule probe of membrane structure was determined. Using this probe the influence of a minor biological membrane component, ganglioside GM1 (GM1), on membrane structure was examined. In addition to structural studies, we also report the use of model membranes as coatings for whispering gallery mode (WGM) label-free biosensors. Using Langmuir-Blodgett/Langmuir-Schaffer deposited bilayers we were able to demonstrate the specific detection of cholera toxin with a membrane containing the glycosphingolipid, GM1. Further studies of lipid coated WGM sensor showed polyethylene glycol (PEG) functionalized lipid bilayers are capable of reducing nonspecific adsorption on sensor surfaces while maintaining functional sites for specific analyte detection. Finally, preliminary studies for expanding the single molecule orientation approach to investigate antibody orientation on sensor surfaces are also reported. Through these studies the utility of both the defocused single molecule imaging technique and model membranes as a tool for biological and sensor applications is demonstrated.
2014-06-18T03:47:36Z
2014-06-18T03:47:36Z
2013-12-31
2013
Dissertation
http://dissertations.umi.com/ku:13148
http://hdl.handle.net/1808/14205
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/306512020-08-25T08:00:57Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-08-24T15:13:18Z
urn:hdl:1808/30651
The mechanism of ion exchange on a synthetic resin, and the application of cation activity coefficient ratios to the interpretation of ion exchange equilibria
Bonner, Oscar Davis
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1951.
2020-08-24T15:13:18Z
2020-08-24T15:13:18Z
1951-05-31
Dissertation
http://hdl.handle.net/1808/30651
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/81192020-08-24T13:12:25Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2011-10-06T16:11:59Z
urn:hdl:1808/8119
Stereochemistry
Leighton, Virgil Louis
2011-10-06T16:11:59Z
2011-10-06T16:11:59Z
1895
Thesis
http://hdl.handle.net/1808/8119
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
oai:kuscholarworks.ku.edu:1808/205352021-08-26T20:40:07Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-03-18T16:18:11Z
urn:hdl:1808/20535
A general conception of acids and bases
Puffett, Dale H.
Thesis (M.A.)--University of Kansas, Chemistry, 1923.
2016-03-18T16:18:11Z
2016-03-18T16:18:11Z
1923
Thesis
http://hdl.handle.net/1808/20535
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/252272020-07-09T21:06:23Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-10-30T22:22:26Z
urn:hdl:1808/25227
Nonlinear Excitation of Photoactivated Molecules: Two-Photon Absorption Spectroscopy, Dynamics, and Quantum Yields
Houk, Amanda Lynn
Elles, Christopher G
Thompson, Ward H
Johnson, Carey K
Dunn, Robert C
Zhao, Hui
Chemistry
Physical chemistry
Higher-Lying Excited States
Nonlinear Excitation
Photoactivated Protecting Group
Photochromic Molecules
Two-Photon Absorption
Ultrafast Spectroscopy
Higher-lying excited electronic states of model, photoactivated molecules are studied using nonlinear excitation to explore the electronic spectroscopy, excited-state dynamics, and reaction quantum yields. The photoactivated molecules studied in this dissertation include two photochromic molecules, stilbene and 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluoro-cyclopentene, that reversibly convert between different isomers following irradiation, as well as a photoactivated protecting group, para-hydroxyphenacyl, that photochemically releases a bound substrate. Studying higher-lying excited states above S1 following nonlinear excitation provides information about the initially excited state, the subsequent excited-state dynamics, and the reaction quantum efficiency. Much less is known about the higher-lying excited states as compared to the well-studied ground and lowest-lying excited states, which motivates the work in this dissertation to investigate the higher-lying excited states of photoactivated molecules following nonlinear excitation. The measurements of the higher-lying excited states reported here include a broadband pump-probe technique that is used to measure the two-photon absorption spectroscopy, as well as the excited-state dynamics following linear and nonlinear excitation of the studied photoactivated molecules. The broadband two-photon absorption spectroscopy measurements reveal the two-photon accessible states and their absolute two-photon absorption cross sections. Separate measurements of the excited-state dynamics and of the reaction quantum yields following nonlinear excitation collectively provide information about the behavior of the higher-lying excited-states, and how the identity of the excited states affect the outcome of the photochemical reactions. Probing the spectroscopy, dynamics, and quantum yields of the studied photoactivated molecules is important to develop a fundamental understanding of photochemical reactions from higher-lying excited states. The spectroscopy, dynamics, and quantum yield measurements in this dissertation can also serve as new benchmarks for computational studies of these model molecules.
2017-10-30T22:22:26Z
2017-10-30T22:22:26Z
2015-12-31
2015
Dissertation
http://dissertations.umi.com/ku:14335
http://hdl.handle.net/1808/25227
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/182072020-06-24T18:58:00Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-07-11T03:52:12Z
urn:hdl:1808/18207
Preparation and reaction of some imidazoles
Asendorf, William Frederick
Thesis (M.S.)--University of Kansas, Chemistry, 1921. ; Includes bibliographical references.
2015-07-11T03:52:12Z
2015-07-11T03:52:12Z
1921
Thesis
http://hdl.handle.net/1808/18207
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/55682020-07-27T13:31:39Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2009-11-02T19:05:24Z
urn:hdl:1808/5568
Dopaquinone as a Common Intermediate in the Biogenesis of Tyrosine-Derived Quinone Cofactors
Moore, Robyn Haley
Mure, Minae
Schowen, Richard L.
Givens, Richard S
Hanson, Paul R.
Scott, Emily E.
Organic chemistry
Ltq
Quinone cofactor
Tpq
Copper amine oxidases (CAOs) are essential for maintaining the level of biogenic amines in the body as well as being involved in the inflammation and immune responses. Lysyl oxidase (LOX), a member of CAO, plays an important role in stabilizing the extracellular matrix but its over-expression has been associated with metastasis/invasion of breast cancer cells. The biogeneses of the topaquinone (TPQ) cofactor of CAO and the lysine tyrosylquinone (LTQ) cofactor in LOX from the corresponding Tyr residue are self-catalyzed processes requiring copper and O2. In CAO, a putative dopaquinone (DPQ) intermediate has been proposed to react with a copper-associated water molecule, through a 1,4-addition mechanism, leading to the formation of TPQ. The D298K mutant of a bacterial CAO produces an iminoquinone tautomer (LTI) of lysine tyrosylquinone (LTQ). The results of this study strongly support the proposal that DPQ is a common intermediate in the biogenesis of these tyrosine-derived cofactors.
2009-11-02T19:05:24Z
2009-11-02T19:05:24Z
2009-06-16
2009
Dissertation
http://dissertations.umi.com/ku:10438
http://hdl.handle.net/1808/5568
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/85292020-08-27T14:56:01Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2011-11-23T18:11:38Z
urn:hdl:1808/8529
The Products of the Destructive Distillation of Keratin in the Form of Leather
Rose, Reed Phillips
2011-11-23T18:11:38Z
2011-11-23T18:11:38Z
1913
Thesis
http://hdl.handle.net/1808/8529
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/312492024-01-16T16:44:29Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2021-01-26T17:47:04Z
urn:hdl:1808/31249
Genetic and Chemical Intervention of the BfrB:Bfd Interaction Dysregulate Iron Homeostasis in Pseudomonas aeruginosa and Affect its Broader Metabolism
Punchi Hewage, Achala Niwanthi Dharmasiri
Rivera, Mario
Desaire, Heather
Lunte, Susan M
Dunn, Robert C
Chandler, Josephine
Hancock, Lynn
Chemistry
Bacterioferritin
BfrB:Bfd
Iron homeostasis
protein-protein interaction inhibitors
Pseudomonas aeruginosa
structure-based drug design
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that is accountable for multiple types of infections, including pneumonia, wound, burn, and urinary tract infections. P. aeruginosa is an emerging threat in the hospital environments and preferentially found in comorbid illnesses. Current treatments for the P. aeruginosa infections recommend the use of combination therapy, a β-lactam with an aminoglycoside or a fluoroquinolone. Also, resistance to such procedures is rapidly emerging. Moreover, P. aeruginosa has been given critical priority for anti-infective development in the 2017 World Health Organization (WHO) report on prioritizing pathogens to guide the discovery of new antibiotics. Iron metabolism in bacteria has gained much more attention as a potential target for antibiotic development. Regulation of iron homeostasis is crucial for cells to have enough iron for growth while avoiding iron-induced toxicity. Iron homeostasis involves iron uptake, storage, and mobilization. Two iron storage molecules co-exist in P. aeruginosa, FtnA, and BfrB. Previous in-vitro studies established the importance of the bacterioferritin associated ferredoxin (Bfd) in iron mobilization from BfrB. The X-ray crystallographic structure and biochemical characterization of the BfrB:Bfd complex identified the hot spot residues of the interaction. The residues E81, E85, and L68 in BfrB, and M1, Y2, and L5 in Bfd majorly contribute to the binding energy. Mutating E81 and L68 to alanine completely inhibited iron mobilization from BfrB. The insights gathered from these in-vitro studies were used in this work to interrogate the importance of the BfrB:Bfd interaction in P. aeruginosa cells. In this work, P. aeruginosa, wild type (PAO1), Δbfd, bfrB(E81A/L68A), and ΔbfrB cells were used to study the significances of the BfrB:Bfd interaction in P. aeruginosa cells. A Native-PAGE method was optimized to image iron in BfrB in P. aeruginosa lysates. This advanced technique allowed us to identify BfrB as the main iron storage protein of P. aeruginosa. The same method was used to image iron storage in BfrB and its subsequent mobilization in P. aeruginosa cells (wild type, Δbfd, and bfrB(E81A/L68A)). The intact BfrB:Bfd interaction capable wild type cells showed maximum accumulation of iron during the early stationary phase, and iron mobilization from BfrB during the late stationary phase. In contrast, the Δbfd and bfrB(E81A/L68A) mutants demonstrated irreversible accumulation of iron in BfrB. Due to the irreversible flux of iron into BfrB, the Δbfd and bfrB(E81A/L68A) mutants developed low cytosolic free iron levels and a high total iron to free iron ratio. The consequences of the genetic blockade of the BfrB:Bfd interaction was further investigated by comparing the expression proteomes of the wild type and Δbfd mutant cells. The iron homeostasis dysregulation affected the iron-dependent and independent metabolic processes in the Δbfd mutant cells. Proteins involved in the TCA cycle, amino acid biosynthesis, oxidative stress regulation, and respiratory chain were under-represented in the Δbfd mutant cells. On the other hand, proteins involved in the iron acquisition systems (pyoverdine, pyochelin, Heme iron acquisition), sulfur assimilation, quorum sensing were over-represented in the Δbfd mutant cells. These findings show that iron homeostasis dysregulation can affect the broader metabolism of P. aeruginosa cells. The chemical intervention of the BfrB:Bfd interaction in P.aeruginosa cells was carried out with small molecule inhibitors, analogs of 4-aminoisoindoline-1,3-dione. These analogs acted on their target, BfrB in P. aeruginosa cells. Moreover, the analogs elicited a concentration-dependent growth retardation, and a pyoverdine hyper-production as a result of cytosolic iron deprivation. Analog-treated cells experienced an irreversible accumulation of iron in BfrB and high total iron content in the treated cells. Hence, the developed 4-aminoisoindoline-1,3-dione derivatives were potent to dysregulate iron homeostasis in P. aeruginosa cells. The BfrB:Bfd inhibitors also potentiated the activity of fluoroquinolones in P. aeruginosa (PA01), and in two cystic fibrosis isolates, MR3B and MR60. The growth impairment of the cystic fibrosis and urinary tract clinical isolates of P. aeruginosa, and Acinetobacter baumannii (AB5075) demonstrate the potential widespread application of the developed 4-aminoisoindoline-1,3-dione derivatives in blocking the BfrB:Bfd interaction. These findings strongly support the suitability of inhibiting the BfrB:Bfd interaction as a novel target in anti-infective development.
2021-01-26T17:47:04Z
2021-01-26T17:47:04Z
2020-05-31
2020
Dissertation
http://dissertations.umi.com/ku:17173
http://hdl.handle.net/1808/31249
https://orcid.org/0000-0003-3711-5162
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/253742018-02-12T18:43:31Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-11-16T03:38:25Z
urn:hdl:1808/25374
Neurochemical Measurements in Animal Models of Neurodegeneration and Neurotoxicity
Kaplan, Sam V.
Johnson, Michael A
Lunte, Susan M
Givens, Richard S
Desaire, Heather
Krise, Jeffrey
Chemistry
Neurosciences
Analytical chemistry
Caged compounds
Chemotherapy
Dopamine
Fast scan cyclic voltammetry
Huntington's Disease
Neurochemistry
This dissertation is a compilation of work in which selected analytical methods, including fast-scan cyclic voltammetry at carbon-fiber microelectrodes (FSCV), were used to determine neurotransmitter release and uptake properties in animals that model neurodegenerative disease and neurotoxicity. Alterations in the release and uptake of dopamine (DA), a central nervous system neurotransmitter that plays an important role in motor function and cognition, could contribute to, as well as be a consequence of, abnormal syndromes associated with neurodegeneration and neurotoxicity. First, we describe the application of FSCV to measure DA release and uptake in animals that model post chemotherapy cognitive impairment (PCCI). PCCI is a complication of chemotherapy treatment that is characterized by a general decline in cognition affecting visual and verbal memory, attention, complex problem solving skills, and motor function. It is estimated that one third of patients who undergo chemotherapy treatment will experience cognitive impairment. To investigate how chemotherapy treatment affects these systems, FSCV at carbon-fiber microelectrodes was used to measure dopamine release and uptake in coronal brain slices of the striatum. Here, we report on two PCCI studies with rats treated with carboplatin or a cocktail containing cyclophosphamide, methotrexate, and 5-fluorouracil (CMF), both of which are composed of clinically relevant chemotherapeutic compounds. Measurements were taken from rats treated weekly with selected doses of chemotherapeutic agent and from control rats treated with saline. It was found that DA release in the striatum is attenuated in chemotherapy-treated rats. Nevertheless, overall dopamine content, measured in striatal brain lysates by high performance liquid chromatography, and reserve pool DA, measured by FSCV after pharmacological manipulation, did not significantly change, suggesting that chemotherapy treatment impairs the dopamine release and uptake processes. Second, we report on regional differences in DA dysregulation in transgenic Huntington’s disease model mice. Huntington’s disease (HD) is a fatal, neurodegenerative movement disorder that is characterized by degeneration of the striatum. It has been determined previously that electrically-evoked dopamine (DA) release is severely attenuated in the dorsolateral striatum of R6/2 HD model mice. Here, we have used fast-scan cyclic voltammetry to uncover regional differences of DA release in the striatum of R6/2 mice. We found a dorsal-to-ventral progressive gradient in single pulse DA release in 6 to 14 week-old R6/2 mice. Moreover, when applying a 120 stimulation pulse-train, we found that DA release was only significantly attenuated in the dorsal striatum. In order to see if regional differences of release were caused by the density of viable dopamine terminals, autoradiographic labeling of the dopamine transporter (DAT) with [3H]WIN 35,428 was performed. It was found that the density distribution of DAT is significantly less in R6/2 mice in comparison to their WT controls; however, there were no significant regional differences. These data collectively suggest that the genetic mutation involved in HD leads to the increased vulnerability of the dorsal striatum in comparison to the ventral striatum, therefore providing insight to the disease mechanism The final project presented here involves the development of a method to combine FSCV measurements with caged compound photo-activation. Caged compounds have been used extensively to investigate neuronal function in a variety of preparations, including cell culture, ex vivo tissue samples, and in vivo. We describe electrochemical measurements used to determine the extent of caged compound photo-activation while simultaneously measuring DA in vitro.
2017-11-16T03:38:25Z
2017-11-16T03:38:25Z
2015-08-31
2015
Dissertation
http://dissertations.umi.com/ku:14210
http://hdl.handle.net/1808/25374
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/253732018-01-31T20:07:48Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-11-16T03:35:53Z
urn:hdl:1808/25373
Synthesis of Novel Sultam Scaffolds: Method and Library Development
Hur, Moon Young
Hanson, Paul R
Altman, Ryan A
Benson, David R
Mure, Minae
Rubin, Michael
Organic chemistry
diversity oriented synthesis
sultam
tetramic acid
The development of methods to produce diverse set of small molecules to be utilized as chemical probes in chemical biology is a continuing emerging area critical in the pursuit of broadening the understanding of biological pathways and search for new therapeutics and biological probes to improve human health. In particular, sultams as non-natural lactam surrogates have recently gained attention as a novel class of compounds with extensive chemical and biological profiles that will be further discussed in introduction to Chapter 1. The virtues of diversity-oriented synthesis (DOS) paired with “Click, Click, Cyclize” paradigm in designing methods and libraries for the production of novel and unique sultam compounds provide a facile and efficient pathway in achieving this goal. Despite these attributes, methodologies for the synthesis of sultams and their corresponding libraries are limited in literature relative to lactam surrogates. A more in detail analysis of this gap will be introduced in the introduction of each chapter. It is the purpose of this dissertation to develop novel methods and production of libraries based on scaffolds generated from these methods. Through these methods and libraries, we aim to produce various sultam compounds that present opportunities in accessing underexplored and underrepresented regions of chemical space with potentials for serving as chemical probes in search for unknown biological activities. An outline of the following chapters of this thesis is shown in Figure A.1. The goal of Chapter 1 is to introduce methods and library development previously reported from the Hanson group. The introduction reviews the libraries that utilize Click “3+2” Huisgen cycloaddition reaction and/or intermolecular nucleophilic aromatic substitution (SNAr) for peripheral diversification. Then efforts on production of two novel sultam libraries based on one-pot Click-aza-Michael of RCM-derived sultam scaffolds and one-pot Click-SNAr of “4+4” derived scaffolds. Chapter 2 introduces a review of recent advances in synthesis of molecules containing triazole motifs via one-pot multicomponent Click reactions (MCR). This review is categorized into three sections, including 2-, 3-component MCR, 4-, 5-, 6-component MCR, and development of novel catalysts for Cu-catalyzed azide–alkyne coupling (CuAAC) reactions. This review will be then followed by studies towards application of one-pot, sequential, multicomponent reaction strategy for the facilitated synthesis of “4+4” dibenzofused 8-membered sultam scaffolds and their analogs produced from 3-, 4-, 5-component reactions. Lastly, Chapter 3 discusses recent advances in the synthesis of various biologically active tetramic acids and their analogs. The review is divided into three sections: synthesis of tetramic acids via Dieckmann reaction, via methods other than Dieckmann condensation, and modification of existing tetramic acids for diversification and studies towards reactivity profile of tetramic acids. Subsequent section of this chapter includes our recent work on synthesis of sultam analogs of tetramic acids via intramolecular sulfa-Dieckmann cyclization. Further diversifications utilizing condensation with isocyanates to produce 3-carboxamide substituted sultam analogs of tetramic acids are reported.
2017-11-16T03:35:53Z
2017-11-16T03:35:53Z
2015-08-31
2015
Dissertation
http://dissertations.umi.com/ku:14182
http://hdl.handle.net/1808/25373
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/104272020-08-07T16:30:08Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2012-11-26T20:55:08Z
urn:hdl:1808/10427
Dopamine Release and Uptake in Animal Models of Neurological Diseases
Fulks, Jenny Lynn
Johnson, Michael A
Fowler, Stephen C
Givens, Richard S
Lunte, Susan M.
Johnson, Carey K
Analytical chemistry
Caged compounds
Chemobrain
Dopamine
Fast scan cyclic voltammetry
Fragile x syndrome
Fast scan cyclic voltammetry (FSCV) can be utilized to detect neurotransmitter release and uptake in brain slices. When combining this technique with disease state animals models, information for therapeutic targets can be obtained. Herein, the evaluation of stimulated dopamine release and uptake in animal models was used in conjunction with pharmacological agents to assess neurological problems caused by Fragile X syndrome and chemotherapy. Fragile X Syndrome, a genetic form of mental retardation caused by a trinucleotide repeat expansion, was investigated by combining behavioral analysis and FSCV to determine alterations in dopamine release, dopamine uptake, effects of amphetamine treatments, and the functionality of the D2 autoreceptor. Side effects of chemotherapy can include alteration in neurological function and were investigated by using FSCV to monitor for effect on dopamine release and uptake patterns in the striatum of rats being dosed with Carboplatin, a chemotherapeutic drug. Finally, instrumentation was established to use caged compounds to photo release glutamate while collecting FSCV data of dopamine release to evaluate instantaneous effects of glutamate on the dopamine system in brain slices.
2012-11-26T20:55:08Z
2012-11-26T20:55:08Z
2011-5-31
2011
Dissertation
http://dissertations.umi.com/ku:11538
http://hdl.handle.net/1808/10427
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/257802019-01-17T17:16:08Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-01-29T18:44:02Z
urn:hdl:1808/25780
ROMP-Derived Alkylating Reagents and Scavengers: Application in Library Development and Sequestration
Faisal, Saqib
Hanson, Paul R
Rubin, Michael
Malinakova, Helena C
Tunge, Jon A
Thomas, Prisinzano E
Chemistry
Alkylating Reagents
One-Pot
ROMP-Soluble
Scavengers
Si-ROMP
Co/C-ROMP
The overarching goal of this dissertation is the development and utilization of (ring-opening metathesis polymerization) ROMP-derived high load phosphorus- and sulfur-based soluble, silica and magnetic alkylating reagents and scavengers. Chapter one begins with a brief introduction of solid phase and solution phase organic synthesis, and next describes the advances in soluble-, silica- and magnetic-immobilized reagents, with a few applications in flow chemistry. Chapter one also outlines the advances in ROMP technology for the synthesis of polymeric soluble, silica and magnetic materials for use as reagents, scavengers and catalysts. Chapter 2 begins with a brief review of immobilized alkylating reagents and next describes the development and utilization of soluble high load ROMP-derived oligomeric triazole phosphates (OTPn) for the efficient (triazolyl)methylation of nucleophilic species in purification free protocols. Chapter 2 finishes with a description of library efforts using a purification-free route that combines MACOS scale-out and ROMP-derived oligomeric triazole phosphates (OTPn) for the generation of a 106-member library of triazole-containing benzothiaoxazepine-1,1-dioxides. In Chapter 3, the first section describes the use of ROMP technology to aid in the development of high-load hybrid silica oligomeric phosphates based alkylating reagents, and their applications for facile benzylation and (triazolyl)methylating of N-, O- and S-containing nucleophilic species. The surface initiated ROMP reaction of Nb-tagged silica particles and functionalized Nb-tagged monomers efficiently yields high-load, hybrid Si-ROMP benzylating (Si-OBP) and (triazolyl)methylating (Si-OTP) reagents. The second section, describes the application of the developed silica-immobilized alkylating reagents in one-pot sequential protocols for diversification of benzothiaoxazepine-1,1-dioxides analogues. The last section of Chapter 3 outlines the synthesis of high-load, hybrid silica-immobilized heterocyclic benzyl phosphate (Si−OHBP) and triazolyl phosphate (Si−OHTP) alkylating reagents for efficient hetero-benzylation and hetero-(triazolyl)methylation and their application in purification-free protocols, which diversify various nucleophilic species. Chapter 4 describes the development and utilization of recyclable magnetic ROMP-derived alkylating reagents and scavengers, immobilized on Co/C magnetic nanoparticles via surface-initiated ROM polymerization. The first section 4.1 outlines the development and application of a high-load magnetic Co/C ROMP-derived oligomeric benzenesulfonate ester Co/C-OBSEn, as an efficient methylating reagent for a variety of carboxylic acids. In addition, an in situ method of methylation/alkylation was developed using Co/C benzenesulfonyl chloride Co/C-OBSCn and corresponding ROH. The desired alkylated products were isolated by simple magnetic decantation and filtration and the spent byproduct magnetic benzenesulfonic acid Co/C-OBSAn was successfully recycled and re-used up to ten times without considerable loss of magnetic material. Section 4.2 details the synthesis and utilization of high-load hybrid magnetic oligomeric phosphonyl dichloride Co/C-OPCn as an efficient scavenger of amines. The magnetic Co/C-OPCn scavenger is employed in amide formations, sulfonylations and urea formations using a variety of amines (used in excess). The coupling products were isolated by simple magnetic decantation and filtrations of reaction mixture. The spent magnetic scavenger was easily isolated by external magnetic decantation and its regeneration is in progress.
2018-01-29T18:44:02Z
2018-01-29T18:44:02Z
2016-12-31
2016
Dissertation
http://dissertations.umi.com/ku:14985
http://hdl.handle.net/1808/25780
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/88032020-09-03T14:36:54Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2012-03-15T14:13:30Z
urn:hdl:1808/8803
The effect of temperature, acid concentration and time on the bromination of phenol for quantitative determinations
Weith, Archie J.
2012-03-15T14:13:30Z
2012-03-15T14:13:30Z
1913-01-15
Thesis
http://hdl.handle.net/1808/8803
en_US
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/222182020-06-23T20:40:51Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2016-12-13T18:54:06Z
urn:hdl:1808/22218
Studies on ethyl benzene and some new derivatives of diphenyl
Andrews, Thelma Maxine
Thesis (M.A.)--University of Kansas, Chemistry, 1930.
2016-12-13T18:54:06Z
2016-12-13T18:54:06Z
1930
Thesis
http://hdl.handle.net/1808/22218
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/191232017-12-08T21:34:34Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-12-04T15:10:04Z
urn:hdl:1808/19123
The synthesis of certain isothiourea ethers and on the preparation of thiazolidins of known structure
Thompson, Willard C.
Thesis (M.S.)--University of Kansas, Chemistry, 1922. ; Includes bibliographical references.
2015-12-04T15:10:04Z
2015-12-04T15:10:04Z
1922
Thesis
http://hdl.handle.net/1808/19123
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/197232017-12-08T21:31:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-01-06T17:16:24Z
urn:hdl:1808/19723
The syntheses and reactions of some iso-thio-hydantoins
Irvin, Roy Robert
Thesis (M.S.)--University of Kansas, Chemistry, 1917. ; Includes bibliographical references.
2016-01-06T17:16:24Z
2016-01-06T17:16:24Z
1917
Thesis
http://hdl.handle.net/1808/19723
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/55762020-07-27T12:42:54Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2009-11-02T19:26:21Z
urn:hdl:1808/5576
Biochemical Characterization and Structure Determination of a Prolyl 4-Hydroxylase-like Protein from Bacillus anthracis
Culpepper, Megen A.
Mure, Minae
Scott, Emily E.
Desaire, Heather
Dunn, Robert C.
Lunte, Susan M.
Analytical chemistry
Procollagen prolyl-4-hydroxylase (P4H) catalyzes the conversion of peptidyl proline to trans-4-hydroxyproline (Hyp). P4H is a member of the alpha-ketoglutarate-dependent mononuclear non-heme iron oxygenase (alphaKG/Fe(II)-oxygenase) family of enzymes, which catalyze a wide variety of reactions. The genome of Bacillus anthracis (B. anthracis), the causative agent of anthrax, contains a gene that is annotated as a p4h based on the predicted amino acid sequence. Recently the immunodominant protein of the B. anthracis exosporium has been identified as BclA. BclA has collagen-like repeat sequences and has a triple helical structure similar to that of animal collagens. We have detected Hyp from the protein extracts of spores of B. anthracis and this is the first report for Hyp detection in bacteria. These results strongly support that B. anthracis contains a P4H-like protein, anthrax-P4H. We have expressed and purified a recombinant form of the putative anthrax-P4H and found that it is a homodimer of 24.3 kDa subunit. The anthrax-P4H exhibits activity and UV-vis spectroscopic properties characteristic of an alphaKG/Fe(II)-oxygenase, and it can bind a collagen-like substrate, (Gly-Pro-Pro)10, with an affinity comparable to that of human type (I) collagen-P4H (human-P4H-1). This is the first report of any P4H-like protein from a bacterial source. We propose that anthrax-P4H can serve as a model for human-P4H-1 from its substrate specificity and kinetic parameters comparable to human-P4H-1. We also report the crystal structure of anthrax-P4H to 1.40 Å. The structure reveals the double stranded alpha-helix core fold (jellyroll) motif, characteristic of Fe(II)/alphaKG oxygenases. The oligomerization of the protein is a homodimeric, alpha2, structure, which makes the anthrax-P4H a new member to the P4H family of enzymes. A putative peptide-binding groove has been proposed based on that identified in the structure of P4H from Chlamydomonas reinhardtii (green alga) (Cr-P4H-1). The anthrax-P4H structure provides insight into the dimeric structure of the alpha-subunits of human-P4H-1, as well as to help understand the mode of substrate recognition that may aide in the development of selective inhibitors.
2009-11-02T19:26:21Z
2009-11-02T19:26:21Z
2009-06-05
2009
Dissertation
http://dissertations.umi.com/ku:10406
http://hdl.handle.net/1808/5576
EN
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/207462017-12-08T21:40:51Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2016-05-03T17:00:25Z
urn:hdl:1808/20746
The fusion curves for the systems pyridine-acetic acid, and ammonia-ortho chlor phenol
Sommerville, Caleb John
Thesis (M.S.)--University of Kansas, Chemistry, 1927.
2016-05-03T17:00:25Z
2016-05-03T17:00:25Z
1927
Thesis
http://hdl.handle.net/1808/20746
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/203712021-08-26T21:40:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-02-25T21:13:04Z
urn:hdl:1808/20371
The action of bromine on Schiff's bases
Wainscott, Jesse Merrill
Thesis (M.S.)--University of Kansas, Chemistry, 1924.
2016-02-25T21:13:04Z
2016-02-25T21:13:04Z
1924
Thesis
http://hdl.handle.net/1808/20371
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/190592018-01-31T20:07:50Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2015-12-03T04:18:15Z
urn:hdl:1808/19059
Nanosynthesis of Iron Based Material for Green Energy
Kirkeminde, Alec
Ren, Shenqiang
Barybin, Mikhail V
Thompson, Ward H
Dunn, Robert C
Wu, Judy Z
Chemistry
Materials Science
Green Energy
Iron Palladium
Magnetic Nanoparticles
Metal Redox
Nanosynthesis
Pyrite
In this work, nanosynthesis of multiple iron-based materials are explored to further their use in green renewable-energy applications. First, the nanosynthesis of the abundant, non-toxic semi-conductor Iron Disulfide (Iron Pyrite, Fool's Gold, FeS2) is investigated. Within these studies, it became possible to tune the shape of the FeS2 nanoparticles easily by modifying injection temperatures and iron precursors. From here, the growth mechanisms of the different shapes were elucidated by examining different time points within the synthesis. It was discovered that the FeS2 did not grow by Ostwald Ripening, but instead by Oriented Attachment. Knowing this, it was possible to not only further the shapes of FeS2 nanoparticles, but also manipulate the size and crystallinity. Focus was then shifted to creating larger micron sized FeS2 crystals. Larger crystals where achieved by a unique FeS nanowire precursor followed by sulfurization. The dominant crystal surface of these crystals could be regulated simply by the time and temperature of the sulfurization. Second, synthetic control of magnetic nanoparticles was examined. A novel synthesis of Iron Palladium (FePd) made possible by interdiffusion of iron into palladium nanocores was identified. Furthermore, a shell of Iron oxide (Fe2O3) could facilely be grown on the FePd nanoparticles, generating a FePd/Fe2O3 core/shell nanoparticle. These FePd/Fe2O3 core/shell particles provided an excellent foundation to create an L10- FePd/α-Fe exchange-coupled nanocomposite that exhibited improved magnetic properties compared to its single phase FePd counterpart. However, the stabilizing ligand used within this FePd synthesis doped into the final nanoparticles, degraded the magnetic properties. iii To overcome the dopant ligand problem, a novel nanoalloy synthetic strategy of Metal Redox was developed. The Metal Redox strategy utilized the inherent reducing power of zero-valent metal sources to create a vast sampling of metal nanoalloys without the need of ligands or excess reducing agents. Stoichiometry of these nanoalloys could be readily adjusted by temperature and explained by simple chemical equilibrium concepts. The Metal Redox methodology was then expanded to shape control and tri-metallic alloys. Finally, the unique MnBi nanoalloy system was created using Metal Redox, making it the first ever reported solution processed formation of this material.
2015-12-03T04:18:15Z
2015-12-03T04:18:15Z
2015-05-31
2015
Dissertation
http://dissertations.umi.com/ku:13913
http://hdl.handle.net/1808/19059
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/267072018-09-08T08:01:11Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-09-07T13:12:27Z
urn:hdl:1808/26707
Some studies of salt effects on solubility in acetic acid
Birdwhistell, Ralph K.
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1953.
2018-09-07T13:12:27Z
2018-09-07T13:12:27Z
1953
Dissertation
http://hdl.handle.net/1808/26707
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/218132018-01-31T20:07:47Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2016-11-03T23:29:43Z
urn:hdl:1808/21813
Increasing the Understanding of Chemical Concepts: The Effectiveness of Multiple Exposures
Bius, Janet H.
Heppert, Joseph A
Barybin, Mikhail V
Desaire, Heather
Patterson, Meagan M
Weis, David
Chemistry
Educational psychology
Cognitive Load Theory
Constructivism
Learning environments
Question difficulty
Symbolic language
Topics
Chemistry is difficult because it has multilevels of knowledge with each level presenting challenges in vocabulary, abstract thinking, and symbolic language. Students have to be able to transfer between levels to understand the concepts and the theoretical models of chemistry. The cognitive theories of constructivism and cognitive-load theory are used to explain the difficulties novice learners have with the subject of chemistry and methods to increase success for students. The relationship between external representations, misconceptions and topics on the success of students are addressed. If students do not know the formalisms associated with chemical diagrams and graphs, the representations will decrease student success. Misconceptions can be formed when new information is interpreted based on pre-existing knowledge that is faulty. Topics with large amount of interacting elements that must be processed simultaneously are considered difficult to understand. New variables were created to measure the number of times a student is exposed to a chemical concept. Each variable was coded according to topic and learning environment, which are the lecture and laboratory components of the course, homework assignments and textbook examples. The exposure variables are used to measure the success rate of students on similar exam questions. Question difficulty scales were adapted for this project from those found in the chemical education literature. The exposure variables were tested on each level of the difficulty scales to determine their effect at decreasing the cognitive demand of these questions. The subjects of this study were freshmen science majors at a large Midwest university. The effects of the difficulty scales and exposure variables were measured for those students whose exam scores were in the upper one-fourth percentile, for students whose test scores were in the middle one-half percentile, and the lower one-fourth percentile are those students that scored the lowest on the exam. The most difficult for all three percentiles were the topics of acid/base equilibria and aqueous equilibria. The exposure variables of recall and algorithmic homework increased student success for all percentiles. Students perform better on exam questions when they understand the terminology and symbolic representations of a topic.
2016-11-03T23:29:43Z
2016-11-03T23:29:43Z
2016-05-31
2016
Dissertation
http://dissertations.umi.com/ku:14525
http://hdl.handle.net/1808/21813
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/241542018-01-31T20:07:52Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2017-05-15T01:11:20Z
urn:hdl:1808/24154
Redox Amination of Isatins
Partridge, James Joseph
Tunge, Jon A
Hanson, Paul
Prisinzano, Thomas
Chemistry
Organic chemistry
Isatins
Redox Amination
Tert-amino effect
This thesis details the development for the synthesis of oxindoles containing an N1-C3 bisindole linkage while simultaneously oxidizing an indoline to an indole. This bond is made via redox amination, meaning no external oxidants or reductants are needed. This method was found to be compatible with a wide range of isatins and was chosen as a strategy for synthesizing a library of oxindoles containing an N1-C3 linkage to either a pyrrole or an indole. Next is detailed attempts to extend the tert-amino effect to make pyrroles, along with unexpected results and preliminary findings. Finally, we report preliminary results on a Pd catalyzed decarboxylative amino allylation of isatins. In this methodology, an allyl amino ester is condensed with isatin. Upon treatment with Pd, decarboxylative allylation occurs to form a 3, 3 disubstituted oxindole containing an allyl group and a free amine. teh only Stoiciometric by-products from this reaction are CO2 and acetone.
2017-05-15T01:11:20Z
2017-05-15T01:11:20Z
2016-08-31
2016
Thesis
http://dissertations.umi.com/ku:14884
http://hdl.handle.net/1808/24154
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/306662020-08-26T08:01:21Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-08-25T20:38:03Z
urn:hdl:1808/30666
Some sulfanilamide derivatives
Duerksen, George Herbert
Chemistry
Pure sciences
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1942.
The preparation and the study of some sulfanilamide derivatives was begum because of the great progress in chemotherapy now being made, and the usefulness of the sulfa compounds especially, in combating various forms of infection. Even though it is realized that the number of compounds synthesized by the chemist is far in excess of those that have been actually investigated for their medicinal value, more and more compounds are steadily being made.
It was with a hope that perhaps some of the compounds synthesized in this study might be investigated further for their medicinal value that
this work was first begun.
2020-08-25T20:38:03Z
2020-08-25T20:38:03Z
1942-08-31
Dissertation
http://hdl.handle.net/1808/30666
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/267612018-09-27T08:01:30Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-09-26T15:28:12Z
urn:hdl:1808/26761
The electrochemistry of elements of the aluminum family in liquid ammonia
McElroy, Albert Dean
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1951.
2018-09-26T15:28:12Z
2018-09-26T15:28:12Z
1951
Dissertation
http://hdl.handle.net/1808/26761
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/302292021-03-05T19:05:09Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2020-03-29T18:05:44Z
urn:hdl:1808/30229
Quantitative Methods to Determine Brain Deposition of Peptides and Proteins after Delivery across the Blood-Brain Barrier
Ulapane, Kavisha Raneendri
Siahaan, Teruna J
Lunte, Susan
Dunn, Robert
Benson, David
Tolbert, Thomas
Analytical chemistry
It is very challenging to develop peptide and protein drugs for treatment of brain diseases because it is difficult to deliver them to the brain due to the presence of the blood-brain barrier (BBB). Therefore, there is an urgent need to develop new and alternative methods to deliver these drugs to the brain for treatment of brain diseases. ADTC5 and HAV6 peptides were derived from the binding sequence of the EC1 domain of E-cadherin protein, and these peptides can enhance the in vivo brain delivery of various molecules through the paracellular pathway of the BBB. Therefore, the overall goal of this project was to evaluate the activity of current and new cadherin cyclic peptides to enhance the in vivo brain delivery of peptides and proteins in rats and mice. The first goal of this project was to evaluate the activity of cadherin peptides (e.g., HAV6, HAV4, cHAVc3, and ADTC5) in delivering peptides (e.g., cIBR and cLABL) and 65 kDa galbumin protein to mouse and rat brains. The brain depositions of peptides and proteins were detected using near IR fluorescence (NIRF) imaging, magnetic resonance imaging (MRI), and mass spectrometry. The brain delivery of unlabeled cIBR7 peptide into rat brains was done to confirm that the intact molecule could be detected in the brain. An efficient extraction method was developed to isolate cIBR7 and ADTC5 from the brain tissue. A novel LC/MS/MS method was developed and validated to quantify cIBR7, an internal standard, and ADTC5 in brain after in vivo delivery. Detection was performed using triple quadrupole tandem mass spectrometry and a multiple reaction monitoring technique. Our results showed a fourfold increase (p = 0.013) in the amount of intact cIBR7 in the brain when it was delivered using ADTC5 compared to cIBR7 alone. The second goal was to compare the activity of ADTC5 and HAV6 peptides in delivering various sized proteins, including IRdye800cw-labeled-lysozyme (15 kDa), albumin (65 kDa), IgG mAb (150 kDa), and fibronectin (220 kDa) into mouse brains. In addition, a quantitative NIRF imaging method was developed to determine brain depositions of these proteins. The results showed that ADTC5 peptide significantly enhanced brain delivery of lysozyme, albumin, and IgG mAb compared to controls; however, no enhancement was observed for fibronectin. HAV6 peptide could enhance the brain delivery of lysozyme, but not the other proteins. The third goal was to design and synthesize new cyclic peptides for better modulation of the BBB. An N-to-C terminal cyclization method was utilized to improve the plasma stability and activity to modulate the BBB of the peptide. Linear and cyclic ADTHAV peptides were designed by combining the sequences of ADTC5 and HAV6. Cyclic HAVN1 and HAVN2 peptides were designed as N-to-C terminal cyclic derivatives of linear HAV6 peptide as new BBB modulator peptides. Binding properties of cyclic ADTHAV and ADTC5 peptides to the EC1 domain of Ecadherin were determined using surface plasmon resonance (SPR), and ADTHAV was found to have higher binding affinity (Kd = 0.114 µM) than ADTC5 (Kd = 26.8 µM). The in vivo activities of these peptides to deliver an IRdye800cw-labeled IgG mAb into the brain were qualitatively and quantitatively determined using NIRF imaging. Cyclic HAVN1 and HAVN2 peptides enhanced brain delivery of IgG mAb compared to HAV6 peptide. Cyclic and linear ADTHAV as well as ADTC5 peptides enhanced brain delivery of IgG mAb. There seems to be a trend that cyclic ADTHAV peptide has better activity than linear ADTHAV under the current conditions (p = 0.07). Overall, these three studies support the potential use of cadherin peptides in transiently modulating the BBB to improve the brain delivery of peptides and proteins
2020-03-29T18:05:44Z
2020-03-29T18:05:44Z
2019-08-31
2019
Dissertation
http://dissertations.umi.com/ku:16778
http://hdl.handle.net/1808/30229
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/208842020-06-30T01:59:10Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2016-05-31T13:42:42Z
urn:hdl:1808/20884
A study of standard cells
Russell, Harold Daniel
Thesis (M.A.)--University of Kansas, Chemistry, 1926.
2016-05-31T13:42:42Z
2016-05-31T13:42:42Z
1926
Thesis
http://hdl.handle.net/1808/20884
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/260182018-04-19T17:45:45Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-02-19T03:28:36Z
urn:hdl:1808/26018
Reorientation Dynamics of Branched and Linear Alcohols
Mesele, Oluwaseun
Thompson, Ward H
Laird, Brian B
Elles, Christopher G
Barybin, Mikhail V
Marshall, Craig
Physical chemistry
Activation Energy
Alcohol Reorientation
Correlation Function
Energy Fluctuation
Vibrational Coupling
Vibrational Spectroscopy
Molecular reorientation of the four isomeric butanols are investigated with molecular dynamics simulations. The purpose of this study is to probe how alcohol reorientational and hydrogen-bond (H-bond) dynamics is influenced by the arrangement of the steric bulk of the isomeric butanols in their liquid state. The OH reorientation times are explained with the extended jump model in which the OH reorientation is broken down into contributions due to ``jumps'' between H-bond partners and ``frame'' reorientation of the intact H-bonded pair. In the case of the isomeric butanols, the model provides a quantitative description of the OH reorientation times. Our results show that reorientation is fastest in iso-butanol and slowest in tert-butanol, while sec- and n-butanol have similar reorientation times. Similar reorientation times for sec- and n-butanol is due to the unpredictable cancellation between the jump and frame reorientation in the two alcohols. Entropic, enthalpic and dynamical factors that include transition state recrossing effects are seen to contribute to the jump reorientation times. Finally, a model that is based on the liquid structure is offered to evaluate the enthalpic and entropic contributions to the jump time. This study represents the foundation for a model that predicts OH reorientation times in alcohols even though further work is needed for a better prediction of frame reorientation times and the transition state recrossing effects. An estimation of the activation energy of chemical reactions like jump reorientation of OH groups in alcohols from molecular dynamics simulations has always required numerous simulations at several temperatures. In this work, several methods for calculating the activation energies at a single temperature have been explored. The applications explored include classical and quantum systems and the activation energy is evaluated using the same time correlation functions that are used to evaluate rate constants from molecular or quantum dynamics trajectories. The use of these time correlation functions show that the activation energy can be evaluated with no extra computational cost. In addition to an analysis of molecular dynamics trajectories, vibrational spectroscopy is a very useful tool for probing structure and dynamics in liquids and the simulation of spectra can be achieved in a variety of ways. Empirical maps for spectroscopic quantities required for the simulation of spectra of OH stretching vibrations are related to the electric field on the hydrogen atom due to the surrounding liquid molecules. Upon the analysis of the four lowest linear alcohols, methanol, ethanol, n-propanol, and n-butanol, it is shown that a single (``universal") map can be used for alcohols with different alkyl groups. Spectra of the OH stretch simulated for the four lowest linear alcohols with this ``universal" map is in very good agreement with those that are simulated using maps that have been optimized for the individual alcohols. However, the spectra resulting from this map differs from that simulated using maps developed for water. The simulated spectra suggest that it may be possible to use one map to simulate OH stretching vibration in other alcohols that are not part of the study. The simulated spectra are very similar to available experimental spectra and the role of non-Condon effects, reorientation dynamics, hydrogen bonding, and spectral diffusion in the simulated spectra are discussed. The Empirical maps developed for the OH stretching vibration of alcohols were used to simulate the IR, Raman, and 2D-IR photon echo spectra of isotopically dilute isomeric butanols. Raman spectra shows that the branched isomers have more weakly bonded alcohols compared to linear alcohols. While the simulation of the vibrational spectra of the OH stretch of isotopically dilute alcohols is relatively straightforward, the accurate simulation of vibrational spectra of the OH stretch in the neat liquids requires a good estimate of intermolecular vibrational coupling. The discrete variable representation method is used to calculate intermolecular vibrational coupling of OH and OD bonds in water. Intermolecular vibrational coupling decreases on H to D substitution and the transition dipole coupling approximation is seen to accurately predict the intermolecular vibrational coupling constant at long intermolecular distances.
2018-02-19T03:28:36Z
2018-02-19T03:28:36Z
2017-08-31
2017
Dissertation
http://dissertations.umi.com/ku:15476
http://hdl.handle.net/1808/26018
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/263022018-04-14T08:01:33Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-04-13T13:32:58Z
urn:hdl:1808/26302
A polarographic study of alpha- and beta-angelicalactone
Kirkland, Earl Vance
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1948.
2018-04-13T13:32:58Z
2018-04-13T13:32:58Z
1948
Dissertation
http://hdl.handle.net/1808/26302
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/75962020-08-06T16:01:19Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2011-06-06T22:57:32Z
urn:hdl:1808/7596
Regioselective acylation of 2-methoxynaphthalene catalyzed by a C-H superacid and chemistry of mercaptoazulenes
Vorushilov, Alexander
Barybin, Mikhail V.
Busch, Daryl
Berrie, Cindy L.
Scurto, Aaron M
Jackson, Timothy A.
Chemistry
Inorganic chemistry
Abstract This Thesis work consists of three Chapters. The first two chapters describe the synthesis and catalytic application of carbon-based superacids and attempts of their immobilization on inorganic supports. Pentafluorophenyl(bis)triflyl methane was synthesized in two steps from pentafluorobenzyl bromide. Due to the strong electron withdrawing nature of the trifluoromethylsulfonyl and pentafluorophenyl groups, the methyne hydrogen atom is exceptionally labile. The para-fluorine atom in the above superacid is labile enough to be substituted by oxygen nucleopiles (hydroxyl and propyloxy). Both the "parent" and 4-substituted acids catalyze highly regioselective acylation of 2-methoxynaphthalene (2-MON) by acetic anhydride. This acylation reaction affords highly valuable 6-methoxy-2-acetonaphthone (2,6-AMN) along with a small amount of 7-methoxy-1-acetonaphthone (1,7-AMN) as opposed to the classic Friedel-Crafts acylation that employs strong Lewis acids such as aluminum trichloride and produces mainly the ortho-acylation product 1,2-AMN. The mechanistic studies described herein suggest that the acylation reaction leading to the formation of the thermodynamically preferred 2,6-AMN is a two step process that involves acylation of 1-position of 2-MON followed by the acyl group transfer to the 6-position of the ring. All of the reaction products - 1,2-AMN, 2,6-AMN, 1,7-AMN and diacetyl-methoxynaphthalene - were isolated or independently synthesized and their structures were confirmed by spectroscopic and mass-spectral methods. The diacylation product was determined to be 1,7-diacetyl-2-methoxynaphthalene, not the 2-acetylaceto-6-methoxynaph-thalene that was previously proposed to be the diacylated species. The acylation of 2-MON was found to be sensitive to the concentration of the catalyst. Lower catalyst loadings (ca. 1 mol %) led to selective formation of 1,2-AMN, while a loading greater than 9 mol % afforded selectively 2,6-AMN and 1,7-AMN 8:1 molar ratio, respectively. The outcome of the reaction was also found to depend dramatically on the solvent medium. Indeed, employing nitromethane as a solvent produced 2,6- and 1,7-AMN, while running the reaction in hexanes resulted in selective formation of 1,2-AMN with a nearly 100% conversion. Only trace amounts of 2,6-AMN were detected when the reaction was conducted in ethyl acetate. Systematic theoretical studies have supported these observations - the relative energies of formation of the acylated products, as well as the relative energies of the corresponding -complex intermediates in nitromethane and hydrocarbons indicate the advantage of 2,6- and 1,7-AMN isomers over the kinetically preferred 1,2-AMN. However, the energy gap in hydrocarbons was too large for the transacylation to proceed. The pentafluoro(bis)triflyl methane and its para-hydroxy derivative were physisorbed on silicon oxide in attempts to immobilize the catalyst on an inorganic support. Both of the silicas have catalyzed acylation of 2-MON with high regioselectivity. The product distribution suggests that the acylation process occurs inside of the pores or on the surface of the silica. However, the catalyst leaches out of the support, making this, method not industrially feasible. The studies of the physisorbed CH acid's catalystic activity supports the hypothesis that once permanently tethered to an insoluble inorganic support, the CH acid would remain a highly active catalyst. A few unsuccessful attempts to chemically bind the catalyst and its derivatives to silicon oxide network have been made. The third Chapter of this Thesis describes synthesis and characterization of a series of mercaptoazulenes, their coordination chemistry and self assembly on Au(111) surfaces. 1,3-Diethoxycarbonyl-2-mercaptoazulene and 1,3-diethoxycarbonyl-6-mercaptoazulene were synthesized from the corresponding haloazulenes in good yields. 1,3-Diethoxycarbonyl-2-mercaptoazulene was decarboxylated to afford 2-mercaptoazulene and 1,3-dicyano-2-mercaptoazulene was synthesized to complete the series. Diethyl 2- and 6-mercaptoazulene-1,3-dicarboxylates react with the dinuclear complex [Au2(dcpm)]Cl2 (dcpm = bis(dicyclohexylphosphino) methane) to give the corresponding bis(thiolate)-digold complexes. Both gold complexes as well as two of the mercaptoazulenes were characterized by XRD. The di-gold motifs in the complexes of 2- and 6-azulenyl thiolates feature strong aurophilic interactions; although the relative orientation of the azulene rings in these species is quite different from the analogous isocyanoazulene complex. All of the mercaptoazulenes have formed air- and moisture stable monolayers on Au(111) films. Characterization of some azulenyl thiolate films was greatly facilitated by incorporation of ancillary nitrile "spectroscopic" handles, a novel approach in the surface chemistry of organic thiols, to the best of our knowledge.
2011-06-06T22:57:32Z
2011-06-06T22:57:32Z
2010-01-01
2010
Dissertation
http://dissertations.umi.com/ku:11251
http://hdl.handle.net/1808/7596
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/210452017-12-08T21:40:51Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2016-06-30T14:47:13Z
urn:hdl:1808/21045
On the constitution of certain thiazolidones derivated from the 2-p-tolyl thiazolidone
Holmberg, Carrol O.
Thesis (M.S.)--University of Kansas, Chemistry, 1927.
2016-06-30T14:47:13Z
2016-06-30T14:47:13Z
1927
Thesis
http://hdl.handle.net/1808/21045
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/203732021-08-27T17:08:13Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2016-02-25T21:13:04Z
urn:hdl:1808/20373
The reduction of organic compounds in liquid ammonia-sodium solutions
Wise, Edwin Charles
Thesis (M.S.)--University of Kansas, Chemistry, 1925.
2016-02-25T21:13:04Z
2016-02-25T21:13:04Z
1925
Thesis
http://hdl.handle.net/1808/20373
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/239832018-11-01T17:17:22Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2017-05-08T02:12:33Z
urn:hdl:1808/23983
Controlling the Cycloreversion Reaction of a Diarylethene Derivative Using Sequential Two-Photon Excitation
Ward, Cassandra Lee
Elles, Christopher G
Thompson, Ward H
Johnson, Carey K
Dunn, Robert C
Fischer, Christopher J
Chemistry
Physical chemistry
Dynamics
Excited State
Photoswitch
Spectroscopy
Two-Photon
Diarylethenes (DAE) are a class of photochromic molecular switches that convert between two structural isomers upon excitation with light. A great deal of research has been dedicated to elucidating the mechanisms of the reversible electrocyclic reactions to make optical memory devices with DAE compounds, but details of the fundamental reaction mechanism after one- or two-photons of light is still lacking. The primary DAE discussed in this dissertation is 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene (DMPT-PFCP), which is a model compound for studying the fundamental reaction dynamics using one- and two-photon excitation experiments. Pump-probe spectroscopy was used to study the low one-photon quantum yield cycloreversion reaction of DMPT-PFCP by changing the excitation wavelength, solvent, and temperature to describe the dynamics on the ground- and excited states. However, the primary goal of this work was to use sequential two-photon excitation with fs laser pulses to map out the cycloreversion reaction dynamics for DMPT-PFCP compound on the first and higher excited states. The cycloreversion quantum yield was selectively increased using sequential two-photon excitation, where after promotion to the S1 state, a second excitation pulse promotes the molecules to an even higher excited state. The mechanism of increasing the yield by promoting the molecules to a higher excited state was explored using pump-repump-probe (PReP) spectroscopy. The PReP experiments follow the excited-state dynamics as the molecules sample different regions of the S1 potential energy surface. The projection of the S1 dynamics onto the higher excited states showed that by changing the secondary excitation wavelength and the delay between excitation pulses, the cycloreversion quantum yield was selectively controlled. Future studies to obtain the specific modes involved in the ring-opening reaction coordinate on the excited-state would further improve our knowledge of the cycloreversion reaction and therefore improve the efficiency of the sequential two-photon excitation process to make very efficient optical memory devices using DAE compounds.
2017-05-08T02:12:33Z
2017-05-08T02:12:33Z
2014-08-31
2014
Dissertation
http://dissertations.umi.com/ku:13495
http://hdl.handle.net/1808/23983
https://orcid.org/0000-0001-6736-6769
en
openAccess
Copyright held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/104282020-08-07T14:51:30Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2012-11-26T20:57:31Z
urn:hdl:1808/10428
Structure/Function Relationships in Nickel-Peptide Complexes: Impact of the Primary Coordination Sphere on Square-Planar Nickel Chemistry
Krause, Mary Elizabeth
Laurence, Jennifer S
Jackson, Timothy A.
Schowen, Richard L.
Scott, Emily E.
Siahaan, Teruna
Chemistry
Biochemistry
Inorganic chemistry
Chiral inversion
Metal abstraction peptide
Nickel
Ni-ncc
Peptide-metal complex
Square-planar
The novel metal-binding tripeptide asparagine-cysteine-cysteine (NCC) is capable of coordinating a metal ion, and we are exploring its use in several biological applications. Different metals may be incorporated into this tag, and when it is placed in line with a peptide or protein that has the potential to be used as a targeting agent, it has the potential to facilitate the diagnosis, treatment, and evaluation of cancers and other diseases. For example, platinum may be used as an anti-cancer therapeutic, whereas nickel generates a catalytic antioxidant. The advantage of this tag is that it is extremely small, is composed of naturally occurring amino acids, and binds metal with unique geometry. Metal binds irreversibly at physiological pH but is released upon modest acidification, as occurs with endocytosis. In order to utilize the tripeptide as a metal-binding tag, it is important to understand the structure, reactivity, and stability of this novel system. Initial studies with nickel established that NCC binds metal with 2N:2S geometry. Electronic absorption, circular dichroism (CD), and magnetic CD (MCD) data collected for Ni-NCC are consistent with a diamagnetic NiII center bound in square planar geometry. This complex acts as a mimic of the enzyme nickel superoxide dismutase (Ni-SOD), which catalyzes the disproportionation of superoxide to hydrogen peroxide and molecular oxygen. Changes in the CD signal of Ni-NCC indicate the optical activity of the complex changes over time, but mass spectrometry data show that the mass of the complex is unchanged, which suggests chiral rearrangement of the complex occurs. Performing the reaction in D2O allows incorporation of deuterium into non-exchangeable positions, indicating chiral inversion occurs at two of the alpha carbon atoms in the peptide. Control peptides were also used to verify the chirality of the final nickel-peptide complex is DLD-NCC. Characterization of the NCC sequence within a longer peptide shows that the geometry of metal coordination is maintained, though the electronic properties of the complex are varied to a small extent due to bis-amide coordination. Chiral inversion does not happen in the same two positions, though initial studies suggest inversion at a different location in the peptide may occur.
2012-11-26T20:57:31Z
2012-11-26T20:57:31Z
2011-05-31
2011
Dissertation
http://dissertations.umi.com/ku:11481
http://hdl.handle.net/1808/10428
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
oai:kuscholarworks.ku.edu:1808/265562018-06-21T08:02:09Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-06-20T15:29:05Z
urn:hdl:1808/26556
Studies on the structure and synthesis of the ipecac alkaloids
Moyer, Melvin Isaac
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1952.
2018-06-20T15:29:05Z
2018-06-20T15:29:05Z
1952
Dissertation
http://hdl.handle.net/1808/26556
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/183422020-06-24T19:52:02Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-08-19T21:02:53Z
urn:hdl:1808/18342
The mono-chlor, mono-iodo derivatives of toluene
Long, Henry Johnson
Thesis (M.A.)--University of Kansas, Chemistry, 1922. ; Includes bibliographical references.
2015-08-19T21:02:53Z
2015-08-19T21:02:53Z
1922
Thesis
http://hdl.handle.net/1808/18342
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/184702020-06-24T18:25:20Zcom_1808_97com_1808_1260col_1808_13944col_1808_7158
2015-09-21T18:30:32Z
urn:hdl:1808/18470
Equilibrium between ferrous and ferric iron when subjected to an alternating current
Robinson, James Gordon
Thesis (M.A.)--University of Kansas, Chemistry, 1915. ; Includes bibliographical references.
2015-09-21T18:30:32Z
2015-09-21T18:30:32Z
1915
Thesis
http://hdl.handle.net/1808/18470
openAccess
This work is in the public domain according to U.S. copyright law and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/262732018-03-31T08:00:58Zcom_1808_97com_1808_1260col_1808_13944col_1808_1952
2018-03-30T17:02:23Z
urn:hdl:1808/26273
I. Polarographic behavior of simple chlorinated organosilanesII. Polarographic investigations in pyridine
Abrahamson, Earl A.
Dissertation (Ph.D.)--University of Kansas, Chemistry, 1951.
2018-03-30T17:02:23Z
2018-03-30T17:02:23Z
1951
Dissertation
http://hdl.handle.net/1808/26273
openAccess
This work is in the public domain and is available for users to copy, use, and redistribute in part or in whole. No known restrictions apply to the work.
University of Kansas
oai:kuscholarworks.ku.edu:1808/78732020-08-13T14:02:45Zcom_1808_97com_1808_1260col_1808_13944col_1808_1951
2011-08-02T19:05:29Z
urn:hdl:1808/7873
Dynamics of Nanoconfined Acetonitrile
Norton, Cassandra
Thompson, Ward H
Laird, Brian B
Jackson, Timothy A.
Chemistry
Physical chemistry
Nanoscience
Acetonitrile
Dynamics
Molecular simulation
Nanoconfinement
Silica pores
The results of dynamics simulations of confined acetonitrile are presented. Confinement is achieved by filling previously formed silica pores having hydroxyl-terminated head groups with liquid acetonitrile. These pores are of the same nominal radius--1.2 nm--and have approximately the same surface coverage of hydroxyl groups, forming a hydrophilic surface. The three-site acetonitrile molecule with parameters previously tested was used for classical molecular dynamics simulations. The main components of interest in the simulations are the diffusion coefficients and reorientational correlation times, two dynamical constants of a given system, and the causes of the magnitudes and variability of each is explored. The acetonitrile molecules are first tested in the bulk system and are shown to yield reasonable results and then are confined in order to extract more information regarding dynamical changes when confinement occurs. Drastic changes are seen when the solvent is confined. The mean squared displacement is used to find the diffusion coefficient both for the whole system and for molecules separated according to where they sit relative to the pore wall or the z-axis. Both of these analyses were performed for calculating the reorientation time by using the reorientational autocorrelation function and then fitting those curves to multi-exponential and stretched exponential functions.
2011-08-02T19:05:29Z
2011-08-02T19:05:29Z
2011-04-27
2011
Thesis
http://dissertations.umi.com/ku:11536
http://hdl.handle.net/1808/7873
en
openAccess
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
University of Kansas
didl///col_1808_13944/100