Chemistry Commons^™

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …

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 …

Charging And Self-Assembly Of Fullerene Fragments, Michael V. Ferguson

Chemistry

Buckybowls are bowl-shaped aromatic polycyclic hydrocarbons that map onto the surface of fullerene molecules, such as C60 and C70, but lack their full closure. They are revered for their ability to undergo multiple reduction reactions, accepting several electrons, due to their degenerate and low energy LUMO orbitals. Corannulene (C20H10), the smallest buckybowl, is well known for its ability to accept up to four electrons. Many studies have been performed targeting preparation and characterization of corannulene anions using the NMR, ESR and UV-vis spectroscopic techniques. Corannulene has also been found to form a solid adduct with C60 without selectivity in its …

Synthesis And Fading Of Eighteenth-Century Prussian Blue Pigments: A Combined Study By Spectroscopic And Diffractive Techniques Using Laboratory And Synchrotron Radiation Sources, Louise Samain, Fernande Grandjean, Gary J. Long, Pauline Martinetto, Pierre Bordet, Jana Sanyova, David Strivay

Chemistry Faculty Research & Creative Works

Prussian blue, a hydrated iron(III) hexacyanoferrate(II) complex, is a synthetic pigment discovered in Berlin in 1704. Because of both its highly intense color and its low cost, Prussian blue was widely used as a pigment in paintings until the 1970s. The early preparative methods were rapidly recognized as a contributory factor in the fading of the pigment, a fading already known by the mid-eighteenth century. Herein two typical eighteenth-century empirical recipes have been reproduced and the resulting pigment analyzed to better understand the reasons for this fading. X-ray absorption and Mössbauer spectroscopy indicated that the early syntheses lead to Prussian …

Improving Student Learning Of Organic Chemistry By The Use Of Case Comparisons., Divine-Favour Ekene Anene

College of Arts & Sciences Senior Theses

No abstract provided.

Pd-­Catalyzed N-­Arylation Of Amides: Catalyst Development And Scope, Tara Brenner

Renée Crown University Honors Thesis Projects - All

Recent development toward more efficient palladium catalyzed amidation reactions has been driven by mechanistic studies and the development of more efficient ancillary phosphine ligands. This review discusses these developments with regard to substrate scope and the nature of the corresponding catalyst systems. Emphasis will be placed on applications of palladium catalyzed amidation reactions and the synthetic utility of these methods.

The Conjugation Of Protein And Peptide Therapeutics To Vitamin B12 For The Oral Treatment Of Diabetes, Jamie L. Bernstein

Renée Crown University Honors Thesis Projects - All

Currently patients with diabetes receive most of their treatments, including insulin, subcutaneously. Developing a method to orally deliver proteins, peptides, and potentially other therapeutics has the ability to increase patient compliance by making treatments easier to administer. Utilizing the Vitamin B12 uptake pathway is one proposed method of oral delivery of protein therapeutics. We investigated a way to synthesize a carboxylic acid derivative of Vitamin B12 (B12) that could increase the ease of its conjugation to proteins and peptides. The 5’-position of the ribose tail of B12 was oxidized using excess 2-iodoxybenzoic acid (IBX) and 2-hydroxypyridine (HYP). The synthesis of …

The Use Of P53-Derived Stapled Peptides As Affinity Isolation Reagents, Kathryn Margaret Headley

Renée Crown University Honors Thesis Projects - All

The transcription factor p53 can induce apoptosis and cell cycle arrest in response to cellular distress. Cancer cells often display increased cell survival. In most cases, this is due to a p53-related defect, such as mutation, deletion, degradation, or sequestration. HDM2 and HDMX are homologous proteins that regulate the function of p53, and their over-expression can lead to an ineffective p53 response. Various inhibitors, including hydrocarbon stabilized alpha-helices of p53 (SAH-p53s), have been developed to target HDM2 and HDMX and restore functionality to the p53 pathway. It has been recently found that SAH-p53 factors also elicit cell death responses in …

Characterization Of Dap2 (Defense-­‐Associated Aspartic Protease-­‐2) In Arabidopsis Thaliana And Determining Its Role In Plant Defense Responses, Kemardo Kitaro Henry

Renée Crown University Honors Thesis Projects - All

Plants defend themselves from invading pathogens by coordinating activity of several plant defense-­‐associated genes. Defense-­‐Associated Aspartic Protease-­‐1 (DAP1) gene of Arabidopsis encodes for an atypical aspartic protease with a putative proteolytic activity. The DAP1 is a negative regulator of plant immunity and the transgenic plants ectopically expressing this genes support pathogen growth and pathogenicity. The Arabidopsis genome has another putative protese that has ~75% homology to DAP1 present in close proximity and therefore was named DAP2. Here, I describe the role of the DAP2 gene in plant defense responses. Two independent knockout dap2 mutants are found to be more susceptible …

Vitamin B12-Based Bioconjugate Probes For In Vitro And In Vivo Imaging, Anna Kahkoska

Renée Crown University Honors Thesis Projects - All

Cancer is the second leading cause of death in the United States. This year, an estimated 577,190 Americans will die as a result of this family of diseases. Finding cancer at its most treatable stage gives patients the greatest chance of recovery; novel imaging agents that target primary and metastasized tumors offer hope for improved prognoses in the future. Based on the hypothesis that vitamin B12 (B12) and its association with specific transport proteins could offer selective access to cancer cell lines, a series of B12-based imaging agents were synthesized, characterized, and assayed for both in vitro and in vivo …

Squaraine Dyes For Two-Photon Fluorescence Bioimaging Applications, Maria Colon Gomez

HIM 1990-2015

No abstract provided.

Examining The Substrate Specificity Of Factor Xiiia Towards Peptide Substrate Modelsac Fibrin Domains., Jacob Bell

College of Arts & Sciences Senior Theses

In the blood coagulation cascade, Factor XIII (FXIII) is a zymogen that is activated by thrombin (IIa) and Ca2+. Activated FXIII (FXIIIa) functions as a transglutaminase in the final steps of the clotting cascade by forming covalent crosslinks between fibrin monomers at reactive glutamine residues. This forms a stable clot structure, secure from proteolytic degradation. To monitor FXIIIa substrate sequence specificity, the glutamine-containing peptide models S. aureus Fnb A (100-114), α2AP(Q4P) (1-15) and K9 (1-10) were introduced to the enzyme in the presence of 15NH4Cl. Using MALDI-TOF MS and 15N HSQC NMR experiments, it was seen that α2AP(Q4P) (1-15) and …

The Investigation Of Protonation Of [Mo2(Nto)2(S2p(Oet)2)2(So)(Sbn)(O2cme)]., Adria Schwarber

College of Arts & Sciences Senior Theses

No abstract provided.

Interaction Between Lubricants Containing Phosphate Ester Additives And Stainless Steels, David W. Johnson, Matthew Bachus, John E. Hils

Chemistry Faculty Publications

One way to improve fuel efficiency in today’s jet aircraft engines is to create an environment for higher operating temperatures and speeds. New and improved lubricants and bearing materials must be developed to remain stable in these elevated operating temperatures. Three lubricants, with varying amounts of tricresyl phosphate added as an anti-wear/extreme pressure additive were tested on two different stainless steels at varying temperatures ranging from 300 °C to 350 °C in vacuum. Significant decomposition of the lubricant base-stocks and the phosphate ester additive did occur in most of the trials resulting in the formation of carboxylic acids and phenols. …

Direct Chain-End Functionalization Of Living Polyisobutylene With Phenoxyalkyl(Meth)Acrylates, Conor Patrick Roche

Master's Theses

This volume describes efforts toward the synthesis and employment of phenoxyalkyl (meth)acrylates, which were used to end-quench 1sobutylene polymers m1tiated from 2-chloro-2,4,4-tnmethylpentane (TMPCl), and 5-tert-butyl-1 ,3-d1(1-chlorol- methylethyl)benzene (bDCC), respectively, at -70 °C in 40/60 (v/v) hexane/methyl chlonde. The quencher/cham end molar rat10s typically ranged from 2.5-4, while the ratio of Lewis ac1d/cham end was vaned from approximately 3 5-6 In all cases, alkylation occurred exclusively at the para position of the quencher and no cham degradat10n was observed, even at high concentrations of TiC14 and long reaction times. Prellmmary qualitative studies mvolved the reaction of quenchers of varymg alkyl tether …

Bombardment Of Graphite And Amorphous Carbon Surfaces Using Molecular Dynamics Simulations: Toward A More Realistic Experimental Model, Marcel Fallet

All Dissertations

Molecular dynamics (MD) simulations are a useful computational tool in fields such as fusion research. Small but vital portions of fusion reactors are essential to their correct operation and longevity. Using the reactive bond order (REBO) and adaptive intermolecular REBO potentials, it is possible to model carbon-based systems, such as graphite diverter plates, under simulated bombardment. The degradation of these plates due to random bombardments from plasma can eventually incur costly shut downs. To gain a better understanding of the atomic-level dynamics that occur when a graphite and amorphous carbon surface undergo energetic, serial bombardment by atoms such as hydrogen, …

Growth And Carboxysome Composition Of The Csosia Pore Mutants Of Halothiobacillus Neapolitanus, Jenifer Milam

Master's Theses

Carboxysomes are specialized organelles that are filled with ribulose 1,5- bisphosphate carboxylase/oxygenase (RubisCO) needed for CO2 fixation. The major carboxysome shell proteins, CsoSl A, B, and C, form hexamers which tile together to form the facets of the thin shell. Each hexamer has a small central pore that may play a role in metabolite flux. Using predicted structural models, a specific amino acid within the conserved hexamer pore motif (Phe-Val-Gly-Gly-Gly-Tyr) was chosen to change the size and charge of the pore, respectively. Two mutants of Halothiobacillus neapolitanus were generated in which the wild type csoSJA gene was replaced with the …

Maxwell's Equations, Ronald Lovett

Topics in Quantum Mechanics

Generating Electromagnetic Waves

Molecular Orbitals: An Introduction, Ronald Lovett

Topics in Quantum Mechanics

No abstract provided.

Chiral Analyses Of Ephedrines, Lyanne Valdez

Honors College Theses

Chiral molecules rotate plane-polarized light and have two or more forms known as enantiomers. We plan to separate the two enantiomeric ephedrines using β-cyclodextrin column in gas chromatography-mass spectrometry (GC-MS).To achieve this, a series of methods were developed through the modification of temperature and mobile phase parameters.

Iron Citrate Toxicity Causes Aco1Δ-Induced Mtdna Loss In Saccharomyces Cerevisiae, Muhammad Ali Farooq

Senior Honors Theses

Aconitase is an enzyme of the Krebs cycle that catalyzes the isomerization of citrate to isocitrate. In addition to its enzymatic activity, Aco1 has been reported to bind to mitochondrial DNA (mtDNA) and mediate its maintenance in the budding yeast S. cerevisiae. In the absence of Aco1, cells rapidly lose mtDNA and become “petite” mutants. The purpose of this study is to uncover the mechanism behind mtDNA loss due to an aco1 deletion mutation. We found that an aco1 mutation activates the mitochondria-to-nucleus retrograde (RTG) signaling pathway, resulting in increased expression of citrate synthases (CIT) through the activation of two …

Synthesis Of Dibenzofurans Via A Palladium Catalyzed Oxidative Ring Closure Reaction, Sadia Akram

Senior Honors Theses

The cannabinoid partial agonist BAY 59-3704 has been identified as an attractive target to explore structure-activity relationships at cannabinoid receptors for the development of a therapeutic agent for psychostimulant addiction. This thesis will describe the studies associated with the optimization of a palladium-catalyzed oxidative ring closure reaction for the synthesisof dibenzofuran analogues from substituted diaryl ethers. These dibenzofurans are viewed as rigid analogues of BAY 59-3704 and will provide useful information about molecular interactions at cannabinoid receptors. The scope and limitations of the palladium-catalyzed oxidative ring closure reaction as it relates to the synthesis of the target dibenzofuran analogues will …

The Electrochemical Analysis Of Bovine Bone Derived Supercapacitors, Organic Peroxide Explosives, And Conducting Polymer Nanojunctions, Paul Goodman

Department of Chemistry: Dissertations, Theses, and Student Research

Electrochemical methods are an extremely diverse set of tools that can be applied to a large number of systems for quantitative, qualitative, and synthetic purposes. For the work described in this dissertation, electrochemical methods provided the basis for the analysis or fabrication of three unique systems.

Chapter 1 describes the analysis of carbon monoliths, produced by the pyrolysis of bovine bone, as electrodes in supercapacitor devices. After pyrolysis of the bone and subsequent removal of the hydroxyapatite support structure, via acid or ethylenediaminetetraacetic acid, a conductive carbon monolith that retains the macroscopic structure of the original bone remains. Analysis of …

Regulation Of Secondary Metabolism In Lysobacter Enzymogenes: Studies Of Intercellular And Intracellular Signaling, Stephen J. Wright

Department of Chemistry: Dissertations, Theses, and Student Research

The organisms of the genus Lysobacter have been recognized as prolific producers of bioactive secondary metabolites, making them potentially valuable as biocontrol agents and as sources of compounds for drug leads. This study was aimed at understanding the regulatory mechanisms that underlie the production of secondary metabolites in our study organism, Lysobacter enzymogenes. Since secondary metabolism is energetically costly, we sought not only to elucidate the biosynthetic chemistry by which the bioactive molecules were constructed, but also the regulation of the biosynthetic machinery. The molecular mechanisms by which L. enzymogenes responds to environmental conditions and transduces signals leading to …

Arachidonate Oxidation Metabolite Profiles For Myoglobin And A Structurally Altered Form Of Myoglobin Produced In Muscle Disease Or Trauma, Kathryn Rae Lawrence

Master's Theses and Doctoral Dissertations

Myoglobin (Mb) and Myoglobin-H (Mb-H) react with glycerophosphocholine (GPC) lipid in the presence of oxygen. This reaction allows the heme group in the protein the chance to induce peroxidation reactions with the lipid. Several aldehyde products of this type of reaction with arachadonic acid have previously been determined, with Mb generating greater quantities of aldehyde products than Mb-H. The focus of this research was to establish the presence of some products from the reactions of Mb and Mb-H with GPC (which contains arachadonic acid) that are more prevalent from Mb-H than Mb, or that only form from the reaction of …

Photopolymerization And Characterization Of Modified Thiol-Ene Networks, Bradley James Sparks

Dissertations

Photopolymerization provides a unique ability to control variables typically uncontrollable using traditional thermally initiated polymerization, thus leading to its use in a broad range of commercial operations. Many of the traditional photopolymers suffer from several setbacks, including oxygen inhibition, unwanted stress buildup which leads to bulk shrinkage, etc., which ultimately lead to diminished polymer performance. The photopolymerization of multifunctional thiols and alkenes has been shown to provide a means to improve upon the weaknesses of traditional photoinitiated polymerizations. The free radical polymerization of thiol and –ene monomers occurs via a series of free radical chain transfer events, as a result, …

Dynamic Bioactive Stimuli-Responsive Polymeric Surfaces, Heather Marie Pearson

Dissertations

This dissertation focuses on the design, synthesis, and development of antimicrobial and anticoagulant surfaces of polyethylene (PE), polypropylene (PP), and poly(tetrafluoroethylene) (PTFE) polymers. Aliphatic polymeric surfaces of PE and PP polymers functionalized using click chemistry reactions by the attachment of –COOH groups via microwave plasma reactions followed by functionalization with alkyne moieties. Azide containing ampicillin (AMP) was synthesized and subsequently clicked into the alkyne prepared PE and PP surfaces. Compared to non-functionalized PP and PE surfaces, the AMP clicked surfaces exhibited substantially enhanced antimicrobial activity against Staphylococcus aureus bacteria. To expand the biocompatibility of polymeric surface …

Biological And Biologically Inspired Polymers For Interface Modification, Lea Clayton Paslay

Dissertations

Naturally occurring macromolecules are produced for a specific function and have the selectivity to accomplish objectives with little waste in energy. The scientific community strives to develop smart, efficient molecules on an economical scale, thus lessons can be learned from nature and applied to cost effective synthetic systems. First, the mimicry of naturally occurring antimicrobial peptides (AMPs) will be described. AMPs show great potential as alternatives to conventional antibiotics as they can selectively bind and eliminate pathogenic bacteria without harming eukaryotic tissues. Aqueous reversible addition–fragmentation chain transfer (RAFT) polymerization was utilized to prepare primary and tertiary amine containing AMP polymer …

Investigations Toward Tunability Of Mechanical, Thermal, And Impact Properties Of Thiol-Ene Networks For Novel High Energy Absorbing Materials, Olivia Devon Mcnair

Dissertations

The UV polymerization of thiols with electron rich alkenes is a highly resourceful reaction that has been utilized by scientists within various disciplines to produce an even more versatile display of applications. This dissertation focuses on a newer application, thiol-ene network (TEN) materials for energy absorption devices. TEN networks display a host of positive polymer properties such as low stress, high optical clarity and uniformity, but they also suffer from unfavorable mechanical properties such as low toughness and elongation at break. The poor mechanical properties demonstrated by TENs prohibit them as choice materials for applications requiring thicker material forms, including …

Synthesis Of Polyhedral Oligomeric Silsesquioxane (Poss) Functionalized Carbon Nanotubes For Improved Dispersion In Polyurethane Films, Xiaonan Kou

Dissertations

Carbon nanotube (CNT) polymer nanocomposites are promising advanced materials. These materials exhibit the advantages of traditional polymeric materials, such as being light weight and easy to process, combined with the potential to exhibit enhanced mechanical, thermal and electrical properties compared to pure polymers. To achieve substantial improvement of composite properties at low CNT loading, uniform dispersion of CNTs in the polymer matrix and strong CNT-polymer interfacial interaction are needed. However, it is difficult to achieve adequate dispersion and interfacial interactions due to the inert nature of CNTs. In this project, polyhedral oligomeric silsequioxane (POSS) will be used as a dispersing …