Chemistry Commons^™

Studies Of The Reaction Of Rongalite With Epoxides, Anuj Aryal

Theses, Dissertations and Culminating Projects

Reactions between Rongalite (Na⁺O^-SOCH₂OH) and epoxides were studied with the aim of developing new synthetic routes for the procurement of sulfone diols. This class of compounds contains essential building blocks in the construction of sulfur heterocycles, which have been implied in the development of several medicinal compounds. Thus far, the desired diols have not been isolated. During control experiments with bromo alcohols, an unknown product was isolated but remains to be identified.

Design Of Block Copolymer With Tunable Hydrophobic/Hydrophilic/Fluorophilic Interactions, Tatiane De Fatima Dutra

Theses, Dissertations and Culminating Projects

Block copolymers (BCP) with balanced interactions and their resultant bulk-phase self-assembly have become increasingly important in advancing nanotechnology, separation, and energy applications. However, a few reports have addressed the synthesis challenge and bulk-phase self-assembly of such triblock copolymers. This thesis presents a facile route for preparing triblock copolymer via controlled radical and organocatalytic ring-opening polymerization that allows precise control over the incorporation of individual moieties in resultant polymer, responsible for balanced hydrophilic, hydrophobic/lipophilic, and fluorophilic interactions. Synthesized polymer with suggested self-assembled 2D lamellar nanostructure exhibits high-temperature stability. The long-term goal of this work is to selectively use this polymer class …

A Computational Study Of The Copper-Catalyzed Trifluoromethylation Of Boronic Acids, Kevin Nyhuis

Theses, Dissertations and Culminating Projects

This work is a computational study of a reaction mechanism for the trifluoromethylation of boronic acids. Three steps of the proposed reaction mechanism are studied, •CF₃ addition to a copper catalyst center, base promoted transmetalation between copper and aryl boronic acid, and bond forming reductive elimination in which the CF₃ and aryl substituent form a bond. Limited information is known about this mechanism. This study uses computational methods to attempt to elucidate the mechanism and provide the groundwork for potential improvement. Quantum chemical methods in conjunction with tight-binding based conformational sampling methods are used to investigate the possible …

Cyclic Sulfones From Double Conjugate Addition Of Rongalite, Hao Zong

Theses, Dissertations and Culminating Projects

We report a cyclic sulfone synthesis method from the addition of sodium hydroxymethanesulfinate to doubly electrophilic dienone substrates. The novel synthesis of the cyclic sulfone thus avoided the using the toxic and odorous sulfides, and also oxidizing reagents. We prepared both the symmetrical and unsymmetrical substrates, and then used the substrate for the synthesis of cyclic sulfone.

Vertical Metal Distributions In Brownfield Soils Drive Enzyme Activities And Plant Success, Eshariah N. Dyson

Theses, Dissertations and Culminating Projects

The distribution of contaminants in polluted soils can vary through depth. We measured the vertical distributions of heavy metals and enzyme activities in the top 10 cm of side-by-side, vegetated and barren brownfield soils. The data showed metals significantly accumulated in the top 2 cm of barren soil and uniformly distributed through vegetated soil. When planted, germination rate was significantly lower in the previously barren soil, with the metal layer intact, compared to mixed barren soil. These data suggest a feedback loop in which plant roots redistribute metals, diluting metal-rich regions, yet germination remains initially limited by a metal cap. …

Investigating The Effects Of Catalytic Activity In Mycobacterium Tuberculosis Indole-3-Glycerol Phosphate Synthase In Wildtype, N189l, And E57d Variants, Sarah S. Cho

Theses, Dissertations and Culminating Projects

Indole-3-glycerol phosphate synthesis (IGPS) is an enzyme that catalyzes the ring closure in 1-(o-carboxylphenylamino)-1-deoxyribulose 5-phosphate (CdRP). Multiple steps are expected to be involved in formation of the pyrrole ring including dehydration, decarboxylation, cyclization, and condensation. IGPS is an essential protein in the pathogen Mycobacterium tuberculosis and a potential target in the treatment of drug-resistant tuberculosis. In order to better understand the function of Mycobacterium tuberculosis IGPS (mtIGPS), we introduced single-point mutations into active site residues. This was based on the hypothesis that introducing mutations would affect the catalysis in a way where we would be able to obtain more information …

Inhibition Of Hsv-1 Binding By Egcg-Stearate, Valerie Paschalis

Theses, Dissertations and Culminating Projects

Herpes simplex virus type 1 (HSV-1) is the causative agent of oral herpes, and is able to establish lifelong latent infection along with painful, recurring symptoms. Epigallocatechin-3- gallate (EGCG) is the most abundant polyphenol derived from green tea (Camellia sinensis), whose anti-inflammatory, antioxidant, anti-cancer, and antiviral properties have been widely studied. Although EGCG is not chemically stable and has poor hydrophobicity, lipophilic derivatives of EGCG have shown increased stability as well as increased antiviral efficacy against HSV. Previous studies have demonstrated that EGCG stearate (EGCG-S), a derivative of EGCG esterified at the 4’ position with stearic acid, is able to …

Elucidation Of Substrate Binding To Photolyase From Sulfolobus Solfataricus Using Isothermal Titration Calorimetry, Amanda Rose Kuerzi

Theses, Dissertations and Culminating Projects

DNA photolyase is a DNA repair enzyme commonly found across the kingdom of life. Binding studies for the hyperthermophilic photolyase derived from Sulfolobus solfataricus (SsPL) may serve to illuminate how DNA photolyase can adapt over a large temperature range. In the first section of this study, the thermodynamics of substrate binding for SsPL in a choline chloride buffer were determined using isothermal titration calorimetry. Using the Counter-Ion Condensation Concept as a model, ionic strength studies were performed to separate the binding interactions into electrostatic, and nonelectrostatic components. The electrostatic interactions do not appear to make a significant contribution to the …

Crispr/Cas9 In Leishmania Genome Editing : Towards A Proof Of Concept, Zein Kasbo

Theses, Dissertations and Culminating Projects

Leishmaniasis is a parasitic Neglected Tropical Disease (NTD) that affects mostly poor countries of the third word due to their limited access to clean water and health care. The disease is transmitted through the bite of a sand fly of the genus Phlebotomus in the Old World, and of the genus Lutzomyia in the New World. Historically, NTDs have not been given adequate attention or research funding and finding curative treatments has been slow. However, the fact that the insect vector and the parasite can live and thrive in any ecological system in the world, and under the current circumstances …

Testing Predicted Specificity Determinants In The Dihydrofolate Reductase Enzyme Family, Seema J. Patel

Theses, Dissertations and Culminating Projects

Dihydrofolate Reductase (DHFR) is an essential enzyme for most organisms, ranging from bacteria to humans. DHFR has essential functions in DNA biosynthesis and cell replication; as a result, cell growth can be inhibited by the inhibition of DHFR. Evaluating the use of well-known DHFR inhibitors is becoming essential in treating infections in the developing world as DHFR is a known target of antibacterial and antiparasitic drugs. Understanding determinants of DHFR inhibitor specificity in terms of amino acid sequence and structure will allow repurposing or designing of new compounds that selectively target DHFR from the pathogenic organism of interest over the …

The Role Of Stress-Activated Protein Kinases In Parasites, Tamara Kreiss

Theses, Dissertations and Culminating Projects

Lymphatic filariasis and leishmaniasis are neglected tropical diseases that are caused by nematode and protozoal parasites. These diseases cause disfiguration, leaving their host socially marked, and in some cases cause more severe disease that can lead to death. These infections, which tend to persist for long periods of time, also lead to bacterial and fungal co-infections, which further exacerbate the disease. Currently there are insufficient treatment options. Current therapies are often too expensive, have toxicity associated with them and are subjected to growing resistance amongst parasite populations. In this thesis I investigated two potential drug targets. The first, is the …

Spectroscopic Investigation Of The Interaction Of Fadh In Dna Photolyase With Uv-Damaged Dna, Kyle Luke Williams

Theses, Dissertations and Culminating Projects

Skin cancer is the most prevalent malignancy found in humans, with the diagnosis rate continuing to steadily increase. The primary cause of this disease is overexposure to harmful ultraviolet (UV) radiation from sunlight, which can induce damage to the nitrogenous bases in DNA via dimerization. The most prevalent UV-induced photoproducts in DNA are cyclobutane pyrimidine dimers (CPDs), most commonly between adjacent thymidines.

Organisms have implemented methods by which to repair these CPDs, the primary of which are nucleotide excision repair (NER) and photoreactivation by photolyases. Photolyases are blue-light activated flavoproteins that are more efficient at recognizing and repairing CPDs than …

Modeling Amyloid-Ss Self-Assembly : Stability Of On-Pathway Aggregate Formation, Andrew Kevin Mauro

Theses, Dissertations and Culminating Projects

Protein misfolding and concomitant aggregation towards amyloid formation is the underlying biochemical commonality among a wide range of human pathologies. Amyloid formation involves the conversion of proteins from their native monomeric states (intrinsically disordered or globular) to well-organized, fibrillar aggregates in a nucleation-dependent manner. Understanding the mechanism of aggregation is important not only to gain better insight into amyloid pathology but also to simulate and predict molecular pathways. One of the main impediments in doing so is the highly stochastic nature of interactions that complicates the development of meaningful insights. In this study, we have utilized a well-characterized intermediate along …

Decoration Of Graphene With Metal Nanoparticles And Its Application For Bioanalysis, Keun Soo Kwon

Theses, Dissertations and Culminating Projects

Graphene is a two-dimensional monolayer of tightly packed sp² hybridized Carbon atoms. Formed from graphite, the theoretical surface area of the monolayer is about 2630 m²/g, and the initial formation of graphene oxide from graphite oxide introduces a variety o f functional groups, such as -COOH, -C=0, and -OH, on its surface. The high surface area and the rich presence of functional groups, along with the potential formation o f sp² bonding networks within graphene oxide, all serve as critical factors allowing for additional chemical modifications. There are extensive research attempts being performed to explore and …

A Leishmania Mitogen Activated Protein Kinase As A Potential Anti-Parasitic Drug Target : Purification, Characterization And Inhibitor Interactions, Aysenur Sayakci

Theses, Dissertations and Culminating Projects

The disease, Leishmaniasis, is caused by the protozoal parasite Leishmania, which is transmitted by the bite of an infected Phlebotomine female sandfly. It is a significant health problem in tropical regions of the world and new therapeutic approaches for treating this disease are urgently needed.

Protozoal MAPKs (Mitogen Activated Protein Kinases) play important roles in parasite viability and infectivity and as such, represent viable drug targets. It has been demonstrated that LmxMPKl is an essential MAPK required for the parasite to establish infection and for proliferation of the amastigote stage (the mammalian stage of the parasite) of the parasite. In …

Conformational Motions Associated With Ligand Binding In Dihydrofolate Reductase From Bacillus Stearothermophilus, Mayam Tobilola Alapa

Theses, Dissertations and Culminating Projects

A fluorescently-labeled, conformationally-sensitive Bacillus stearothermophilus (Bs) dihydrofolate reductase (DHFR) (C73A/S131C_MDCC DHFR) was developed and used to investigate kinetics and protein conformational motions associated with methotrexate (MTX) binding. This construct bears a covalently attached fluorophore, N-[2-(lmaleimidyl) ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC) attached at a distal cysteine, introduced by mutagenesis. The probe is sensitive to the local molecular environment, reporting on changes in the protein structure associated with ligand binding. Intrinsic tryptophan fluorescence of the unlabeled Bs DHFR construct (C73A/S131C DHFR) also showed changes upon MTX association. Stopped-flow analysis of all data can be understood by invoking the presence of two native state DHFR …

The Applications Of Graphene And Its Derivatives For Heavy Metal Removal, Clemonne John Madarang

Theses, Dissertations and Culminating Projects

Heavy metal pollution is very prevalent in our environment. The entire removal of heavy metal and organic contaminants in natural water resources will not only affect the environment itself, but also can block the toxic contaminant transfers in food chains. Currently, there are many studies being done to remove these heavy metal ions from our water, such as reduction reactions, chemical precipitation, reverse osmosis and electrolytic recovery. One of the promising techniques is adsorption. The focus of this research is using graphene and its derivatives, such as silylated graphene oxide (GO), to adsorb heavy metals, specifically, lead. This research describes …

Investigation Of Charge Recombination In Escherichia Coli Photolyase And Vibrio Cholera Cryptochrome Dash, Agnieszka Zieba

Theses, Dissertations and Culminating Projects

Proton-coupled electron-transfer (PCET) is a mechanism of great importance in protein electron transfer and enzyme catalysis, and the involvement of aromatic amino acids in this process is of much interest. The DNA repair enzyme photolyase provides a natural system that allows for the study of PCET using a neutral radical tryptophan (Trp‘). In Escherichia coli photolyase, photoreduction of the flavin adenine dinucleotide (FAD) cofactor in its neutral radical semiquinone form (FADH') results in the formation of FADH and Trp . Charge recombination between these two intermediates requires O A/T # the uptake of a proton by ~ Trp . The …

Preparation And Crystal Structures Of Chiral And Non-Chiral Mixed Ligand Copper Complexes Containing N-Methyl Imidazole And Various N-Phthaloylalanines, Hiral Patel

Theses, Dissertations and Culminating Projects

A quasiracemate is the cocrystallization of two similarly shaped but chemically distinct molecules of opposite handedness. There has been extensive work done in the field of organic quasiracemates by Dr. Kraig A. Wheeler. Limited work has been done in inorganic quasiracemates. The goal of this study was to prepare various metal based enantiomers, racemates, and quasiracemates using A-phthaloylalanines, and TV-methylimidazole as ligands bound to copper arranged in a centrosymmetric pattern. In this study, we developed a method to prepare A-phthaloylalanines and its copper complexes. Three complexes have yielded crystal structures: a racemate, bis(7V-methylimidazole) bis(D,L-3-chloro-7V-phthaloylalanato)copper(II); a quasiracemate, bis(A-methyhmidazole)(L-3-chloro-iV-phthaloylalanato)(D-3-methyl-7V-phthaloylalanato) copper(II); and an …

Conformational Motion Associated With Catalysis In Indole-3-Glycerol Phosphate Synthase From S. Solfataricus, Tomasz Kurcon

Theses, Dissertations and Culminating Projects

Indole-3-glycerol phosphate synthase from Sulfolobus solfataricus (SsIGPS) belongs to a broad family of (βα)₈-barrel enzymes. It catalyzes the fifth step in tryptophan biosynthesis, converting l-(o-carboxylphenylamino)-l-deoxyribulose-5-phosphate (CdRP) to indole-3-glycerol phosphate (IGP). Site selective mutagenesis was used to introduce a single cysteine in two loops near the active site, generating two recombinant proteins, each containing a single cysteine handle. The two construct were labeled, each with two different thiol-reactive probes generating four labeled constructs that were used for this study. Steady-state kinetic parameters of the labeled mutants and the wild type SsIGPS were well characterized using fluorescence spectroscopy. Subsequent experiments …

Vibrational Spectroscopy Of Isotopically Labeled Indoles And Electron Transfer Involving Indole (Tryptophan) Radicals, Senghane Dominique Dieng

Theses, Dissertations and Culminating Projects

Vibrational spectroscopy of tryptophan can be used as a probe for local protein conformation and to study protein electron transfer. For the interpretation of the vibrational spectra, the proper assignment of the vibrational bands to normal modes is essential. We report the experimentally measured infrared and Raman spectra of tryptophan, indole and 3-methylindole as well as of several of their isotope substituted forms; tryptophan indole-d₅ and -¹⁵N₂, and indole 2-¹³C. The effect of the exchange of the indole NH to ND on the vibrational spectra of these molecules was also determined. The measurements …

A Fluorescent Photoinduced Electron Transfer (Pet) Sensor For Cations With A Separate Pet Channel To Suppress Proton Signals, Supun Pathirana

Theses, Dissertations and Culminating Projects

This thesis presents A-((10-((2-methoxy-4-methylphenoxy)methyl)anthracen-9- yl)methyl)(pyridin-2-yl)-A-((pyridin-2-yl)methyl)methanamine, 1, a photoinduced electron transfer (PET) sensor that acts as a fluorescent ‘Off-On’ switch in the presence of Zn ions and not sensitive to protons.

Optimization Of Expression And Purification Of Acetoacetyl-Coa Thiolase From Sunflower, Anthony Muriithi Maina

Theses, Dissertations and Culminating Projects

The [beta]-oxidation system in sunflower (Helianthus annuus L.) cotyledons is distinguished by the existence of two different thiolase isoforms, Thiolase I (acetoacetyl-CoA thiolase, EC 2.3.1.9 AACT) and Thiolase II (3-oxoacyl-CoA thiolase, EC 2.3.1.16 OACT). Glyoxysomal AACT is the last enzyme in the p-oxidation of fatty acids in plant glyoxysomes. Glyoxysomal AACT has been successfully cloned, expressed and purified from sunflower cotyledons (Dyer et al., 2006). In this paper we investigate the optimal conditions for both expression and purification. These include the choice of vector, the growth conditions and the purification parameters for the maximum possible yield of AACT protein.

Identification Of Metallo-Ss-Lactamase Inhibitors Via Enzyme Assay And Hplc-Ms Monitoring, Peggy Ann Sanchez

Theses, Dissertations and Culminating Projects

The vast overuse of antibiotics along with extrachromosomal gene insertion between different bacterial species has led to the Darwinian consequence of antibiotic resistance. Amongst the contributing factors to the rise of bacterial resistances are the production of ß-lactamases, which pose a major impediment to treatment with ß-lactam drugs such as penicillins and carbapenems. SPM-1 is a metallo-ß-lactamase (MBL) that confers antibiotic resistance to bacteria through zinc-mediated hydrolysis of ß-lactams. Bacteria that express the SPM-1 metalloenzyme show reduced sensitivity to ß-lactam drugs. One method to defeat this form of resistance is to administer a ß-lactam antibiotic with a potent ß-lactamase inhibitor …

Fluorescent Photoinduced Electron Transfer (Pet) Proton Sensors, Risper Nyabeta

Theses, Dissertations and Culminating Projects

Two new fluorescent photoinduced electron transfer (PET) proton sensors based on anthracene and pyrazoline chromophores have been prepared. The anthracene sensor was prepared through alkylation of 2-pyridylcarbinol with 9-chloromethylanthracene and the pyrazoline sensor was prepared through an aldol condensation of 4- carboxybenzaldehyde and acetylpyridine followed by reaction with phenylhydrazine. The fluorescence of these sensors is modulated by the initiation or quenching of a PET process between the chromophore and a receptor due to protonation. The synthesis, characterization and proton binding studies of the new sensors are reported in this thesis.

Fluorescent Photoinduced Electron Transfer (Pet) Cation Sensors Derived From Natural Products, Kenny Loo

Theses, Dissertations and Culminating Projects

Two new second generation fluorescent switches that are based on the chromophore-spacer-receptor architecture are reported in this thesis. The fluorescence modulation of these switches is a result of quenching or initiating photoinduced electron transfer (PET) between the chromophore and the receptors due to cation binding. These two molecules utilize an alkaloid, anabasine, as the proton receptor, and function as fluorescent off-on-off switches with decreasing pH. One of these molecules also utilizes a coumarin as the chromophore, making it the first rationally designed fluorescent PET system based on natural products. Further studies of two well-known first generation fluorescent switches to achieve …

Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The increasing practice of industrial-scale agriculture tends to concentrate large masses of animal waste in relatively compact areas, potentially leading to excessive release of polluting nutrients into waterways during major storms. Anaerobic treatment conditions are generally favored to conserve nitrate N as an agricultural commodity. However, overall N contents in waste are often in excess of crop fertilization needs: storing excess N in soluble nitrate form increases pollution potential. Thus the perceived needs of agriculture and society-at-large become at odds. Organic nitrogen forms (e.g., proteins) are more environmentally stable and are less subject to unintentional release. Although U.S. farmers tend …

A Biogeochemical Comparison Of Fossil (Carboniferous) And Modern Crustose Red Algae, Michael A. Kruge, John E. Utgaard, William Ferry

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The nature of the contribution of the various types of algae to sedimentary organic matter continues to be a topic of research interest. Crustose red algae have however received less attention than other types. The fossil calcareous red algae (Rhodophyta) analyzed in this study are two relatively unrecrystallized specimens of Parachaetetes (Family Solenoporacea) from the lower part of the Ste. Genevieve Formation (Carboniferous, Visean) in Union County, Illinois, USA. They occurred in the patch reef phase of a small carbonate mudmound-patchreef. The three modern specimens (collected and identified by F. Collier) are the crustose algae Lithothamnion, Clathromorphum and Phymatolithon …