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Pro- And Antioxidant Activity Of Selenomethionine: Preventative Measures Against Metal-Mediated Dna Oxidation, Austin Mroz

Graduate Theses - Chemistry and Biochemistry

DNA damage by reactive oxygen species (ROS) has been linked to several diseases.

Antioxidants are one method of combating the effects of ROS; selenium-containing antioxidants have shown promise in alleviating in vitro DNA damage. This study aims toelucidate the effects of selenomethionine (SeMet) on DNA damage mediated by Cu(II),Fe(II), or Cr(III) metal ions. HPLC analysis was used to probe the oxidative effects of SeMet by quantifying the oxidative damage marker, 8-hydroxy-2’-deoxyguanosine. Prior literature indicates that the antioxidant activity of SeMet is potentially concentration dependent; however, HPLC results in this study indicate a metal-ion dependency. In order to better understand the …

Do Halogenated Natural Products Bioaccumulate In Narragansett Bay?, Christine Gardiner, Anna Robuck, Rainer Lohmann

Senior Honors Projects

In recent decades, a new family of chemical compounds has begun to garner research attention—halogenated natural products, or HNPs. These chemicals are produced by algae, bacteria, worms, and sponges, and many are structurally similar to harmful manmade compounds, such as polychlorinated diphenyls (PCBs), or brominated flame retardants (PBDEs), which are known to cause cancer, reproduction issues, endocrine disruption, and death. While HNPs are produced naturally, they are still considered pollutants because of their bioaccumulative behavior and apparent toxicity.

Currently, there is limited research on their presence and effects, with a few studies from Europe and the Pacific highlighting their importance …

Application Of Dft-Derived Relationships Between Chemical Environment And ²⁹Si Nuclear Magnetic Resonance Spectroscopy To Determine Structure In Silicon Oxycarbide Ceramics, John Paul Nimmo

Chemistry & Biochemistry Theses - Archive

Silicon oxycarbide (SiCO) is an amorphous ceramic material widely used in industrial applications, for its useful electronic and biologically-compatible properties.1-3 SiCO is resistant to crystallization, remaining amorphous even above temperatures at which amorphous SiO2 would crystallize. Though silica (SiO2¬) and silicon carbide (SiC) are almost immiscible, it is useful to consider the material as a phase composition of these along with carbon, according to the formula below. The first two terms in braces can be considered as being the “SiCO glass” into which a third term representing excess or “free” carbon is incorporated as graphite-like nano-flakes and bands. SiC_x O_y={y/2 …

Modeling Etr1 With Isolable Coinage Metal Complexes Supported By Partially Fluorinated, And Methylated Scorpionates, Shawn Glen Ridlen

Chemistry & Biochemistry Dissertations - Archive

Ethylene is a small molecule that functions as a plant hormone that is closely associated with several vital plant functions ranging from germination, shoot and root growth, sex expression, fruit ripening, senescence and abscission. This gaseous hormone is produced by almost every part of the plant, and mediates these processes throughout out the life of the plant. The ethylene response in many plants is initiated by a group of 5 copper based membrane bound receptors, mainly ETR1 (ethylene receptor 1). These receptors are made up of homodimers linked at their N-termini by two disulfide bonds. Each of the monomer units …

Gas Chromatography And Metal Analysis Of Produced Water Treated With A Household Commercial Filter, Chuong Nguyen

Chemistry & Biochemistry Theses - Archive

Unconventional oil and gas extraction activities, including hydraulic fracturing, are a collection of processes used to liberate significant quantities of natural gas and oil in the United States. Many extraction sites are located in large cities, close to residential areas. In some cases, operational malfunctions can result in spills of thousands of gallons of produced waste water and pose a threat of contaminating underground or surface water resources. Produced water contains a complex mixture of salts, volatile and semi-volatile organic compounds, metals, organic acids, and particulates, as well as additives from the drilling process. In this study, we tested the …

Synthesis Of Substituted Tetrahydropyrans Using Metal-Catalyzed Coupling Reaction, Amanda Lieu

Renée Crown University Honors Thesis Projects - All

The purpose of this research is to explore the use of cobalt- and iron-catalyzed cross coupling reactions of alkyl iodides containing beta-tetrahydropyran groups to develop a general method to synthesize substituted tetrahydropyrans. Substituted tetrahydropyrans can be used towards the total syntheses of biologically active natural products. The starting iodide compounds underwent sp3-sp3 and sp3-sp2 cobalt- and iron-catalyzed cross-coupling reactions with different Grignard reagents. It was expected that the formation of the coupled product would be faster than the formation of the side products (elimination and homocoupling) and thus yield the desired substituted tetrahydropyrans. The results of this study showed that …

Mid-Scale Instrumentation: Regional Facilities To Address Grand Challenges In Chemistry, Robert Hamers, Sophia Hayes, Graham Peaslee

Chemistry Faculty Research

A regional workshop sponsored by the National Science Foundation, Arlington, Virginia, September 29-30, 2016. To determine what needs and opportunities might exist for mid-scale instrumentation (MSI), two workshops were held in fall of 2016 to explore opportunities within the discipline that could be provided by such investment. One workshop was convened to explore the need for co-localization of existing instrumentation at a regional or cyber-enabled facilities (addressed in this report, “Mid-Scale Instrumentation: Regional Facilities to Address Grand Challenges in Chemistry”). In this report, we identify different areas where investment in such MSI facilities would be highly beneficial. These appear as …

Synthesis Of Polythioether Nanoparticles Via Thiol-Alkene/Alkyne Photopolymerization In Miniemulsion, Susan E. Walley

Honors Theses

Emulsion-based processes – such as miniemulsion polymerizations – provide well-studied synthetic routes to polymer nanomaterials. Miniemulsion polymerizations are characterized as aqueous dispersions of small, narrowly distributed monomer droplets created through high shear and stabilized against Ostwald ripening/collisional degradation by addition of an appropriate surfactant and costabilizer. In this work, thiol–alkene/alkyne photopolymerization in miniemulsion is demonstrated as a simple, rapid, and one-pot synthetic approach to polythioether nanoparticles with tuneable particle size and clickable functionality. Nanoparticles with mean particle diameters ranging from 45 nm to 200 nm were synthesized through simple modifications to the miniemulsion formulation and processing parameters. Facile access to …

Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, Ashley N. Henderson

Graduate Theses and Dissertations

Designed transmembrane peptides were employed for investigations of histidine residues within the hydrophobic environment of the lipid bilayer by means of oriented solid-state deuterium NMR spectroscopy. Using the model peptide GWALP23 sequence (GGALW(LA)6LWLAGA) as a host framework, the effects of single and double histidine mutations were explored. Replacement of leucine residue 12 to polar neutral histidine had little influence on the peptide average orientation, however under strongly acidic pH conditions in DOPC bilayers, the histidine becomes positively charged (pKa 2.5) and the GWALP23-H12 peptide exits the membrane and adopts a surface-bound orientation. Conversely, mutation of leucine 14 to neutral histidine …

Controlled Synthesis And Utilization Of Metal And Oxide Hybrid Nanoparticles, Cameron Cowgur Crane

Graduate Theses and Dissertations

This dissertation reports the development of synthetic methods concerning rationally-designed, hybrid, and multifunctional nanomaterials. These methods are based on a wet chemical, solution phase approach that utilizes the knowledge of synthetic organic and inorganic chemistry to generate building blocks in solution for the growth of nanocrystals and hybrid nanostructures. This work builds on the prior knowledge of shape-controlled synthesis of noble metal nanocrystals and expands into the challenging realm of the more reactive first row transition metals. Specifically, a microemulsion sol-gel method was developed to synthesize Au-SiO2 dimers as precursors for the synthesis of segmented heterostructures of noble metals that …

Genetically Encoded Fluorescent Protein Biosensor For Nitric Oxide, Wenjia Zhai

Department of Chemistry: Dissertations, Theses, and Student Research

Nitric oxide (NO) is an important molecule in living cells for signaling, thus a specific sensor to detect its level in live cells is needed. Currently there are a few small molecule probes for the detection of NO. A common shortcoming of these probes is their unavoidable leakage from the target cells. In this project, I seek to develop a novel green fluorescent protein (GFP)-based biosensor to detect cellular NO. This GFP-based sensor is genetically encodable and can potentially avoid the possible false positive result due to the leakage. I synthesized an unnatural amino acid (unAA) and examined its incorporation …

Molecular Basis Of Substrate Recognition In Bjai, An Ahl Synthase From Bradyrhizobium Japonicum, Nicole Cornell

Boise State University Theses and Dissertations

Resistance to antibiotics has become a major challenge in today’s society for treating bacterial infections. Inhibition of quorum sensing has a potential to be a non-antibiotic based therapeutic that could be used to fight these bacterial infections. Quorum sensing is a cell density dependent, intercellular communication mechanism that bacteria use to synchronize behavior such as virulence and resistance to antibiotics. If this switch from planktonic to communal behavior can be inhibited, the bacteria will be less virulent. One possible way to accomplish this is by inhibiting the enzymes that are responsible for making the quorum sensing signaling molecules in Gram-negative …

Synthesis, Characterization And Biological Studies Of Technetium-99m And Rhenium-188 Peptides, Vanessa Anne Sanders

UNLV Theses, Dissertations, Professional Papers, and Capstones

Radiopharmaceuticals are very powerful diagnostic tools for evaluation of a host of medical conditions. These drugs are labeled with radioactive isotopes, which are utilized to create pictures of areas of interest through absorption of the drug. They are currently in high demand due to their ability to image areas that traditional imaging devices cannot. The radioisotope 99mTc, with a half-life of 6.01 hours and a 140 keV gamma emission, is central to many radiopharmaceutical compounds. This isotope is easily obtained from a 99Mo-99mTc generator, through beta decay and column chromatography separations. Very little technetium, less than 6 ng, is needed …

A Targeted Drug Delivery Strategy For Trypanosomiasis Towards A Diastereoselective Boronate Ester Mediated Intramolecular Diels-Alder Cycloaddition, Heeren Manoj Gordhan

All Dissertations

Human African trypanosomiasis (HAT), commonly called African sleeping sickness, is caused by bloodstream form Trypanosoma brucei and has the potential to affect millions of people in sub-Saharan Africa. Treatments have existed for the past fifty years, but are characterized by severe adverse side-effects and poor efficacy. Trypanosomes generate ATP through glycolysis, or the metabolism of glucose, which is catalyzed by enzymes called hexokinases (TbHK1 and TbHK2) in trypanosomes. Through high-throughput screenings (HTS) and structure-activity relationships (SAR), both hexokinases could be targeted with small molecules to inhibit the first step in the glycolytic pathway of trypanosomes. Of the two hexokinases, TbHK1 …

Studies Towards The Synthesis Of (-)-Centrolobine Via The Carbonyl Ene Reaction Of Exocyclic Enol Ethers, Brianna Shores

Renée Crown University Honors Thesis Projects - All

The goal of this study is the synthesis of centrolobine 7, a naturally-occuring compound that exhibits anti-parasitic and anti-inflammatory activity.

The strategy is to utilize the carbonyl ene reaction to form the 2,6-disubstituted framework of centrolobine 7 from exocyclic enol ether 110 and aldehyde 111. Exocyclic enol ether 110 would be synthesized via literature procedures starting from commercially available glutaric anhydride 11 and anisole 114.

The work completed to date optimizing the following reactions: Friedel-Crafts acylation of glutaric anhydride 11 and anisole 114, the reduction of alcohol 116, and cyclization of alcohol 116 to lactone …

Phospholipase Dζ Enhances Diacylglycerol Flux Into Triacylglycerol, Wenyu Yang, Geliang Wang, Jia Li, Philip D. Bates, Xuemin Wang, Doug K. Allen

Faculty Publications

Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase D_ζ genes (AtPLD_ζ1 and AtPLD_ζ2) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG …

Fluorescence And Uv-Vis Studies Of Quinone-Induced Protein Modifications, Charles A. Thomas Jr

Honors Theses

Quinones are the metabolites of a class of chemicals known as polycyclic aromatic hydrocarbons. These chemicals have been found to be toxic in the environment, especially when interacting with certain proteins. In this study, we investigated the modification of Lysozyme and Ribonuclease A by a series of benzoquinones as well as few naphthoquinones. Fluorescence spectroscopy was used to measure the degree of modification of Lysozyme and Ribonuclease A when incubated with quinones at differing concentrations and for various times. All reactions, unless noted, were carried out in a phosphate buffer (pH=7.0) at 37°C to mimic physiological conditions. The fluorescence intensity …

A Study Of The Photoacoustic Effect In Ethylene Gas, Jay Nguyen

Honors Theses

Ethylene, C2H4, is a plant hormone produced and released naturally by plants and soil microorganisms. This colorless, flammable gas has a slightly sweet odor usually only recognized by those who have handled ethylene before. In situ analyses of this gas and many other potentially harmful gases outside of the laboratory are often difficult to perform due to the lack of a portable yet reliable unit capable of precisely and accurately detecting and measuring the concentrations of these gases at trace gas concentrations of a few parts per billion. In this research project, photoacoustic spectroscopy was used to detect and measure …

Design, Synthesis And Characterization Of New Analogs Of Tetraiodothyroacetic Acid (Tetrac) As Novel Angiogenesis Modulators And Their Binding Studies With Αvβ3 Integrin, Mary Adeyeye

Chemistry

Angiogenesis is the formation of new blood vessels from preexisting blood vessels. Design and development of novel angiogenesis inhibitors has been validated as a target in several tumor types. Integrins are important ligands that play a critical role in the angiogenesis process, particularly blood formation and local release of vascular growth factors, and they are members of a family of cell surface receptors. Tetraiodothyroacetic acid (tetrac), a deaminated derivative of thyroid hormone T4, is a thyroid antagonist and blocks the actions of T3 and T4 with an interaction site that is located at or near the RGD recognition site identified …

Determining The Role Of Secondary Structure In Translational Control, Dhruv S. Patel

Chemistry

The central dogma of cellular biology asserts that DNA is transcribed to mRNA, which in turn is translated to a protein. This simplistic conduit of gene expression is heavily regulated at multiple levels to ensure proper temporal and spatial expression of genes. One such mode of regulation occurs at the juncture at which RNAs are translated to proteins, known as translational regulation. mRNAs can be translationally regulated by trans-acting factors, such as RNA binding proteins (RBPs), and/or cis-acting factors. Regulation via these two modalities can depend on structure as well as RNA sequence. Secondary structures, such as stem loops, are …

Differentiation Of Hair Using Atr Ft-Ir Spectroscopy: A Statistical Classification Of Dyed And Non-Dyed Hairs, Matthew S. Boll

Chemistry

Although hair is one of the most common and abundant types of evidence found at a crime scene, the current forensic analyses employed underutilize its full potential evidentiary value. Microscopy is the fundamental technique used to analyze forensic hair evidence, but even this routine and well-accepted method has limitations. In this study, non-dyed and dyed hairs from individuals varying in race, biological sex, and age, were analyzed using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. Through the incorporation of multivariate statistical analysis, spectra collected from dyed and non-dyed hairs were differentiated with high accuracy. After hair spectra were determined …

Bioinspired Design Of Wetting And Anti-Wetting Surfaces Via Thiol-Ene Photopolymerization, Li Xiong

Dissertations

Surface wettability is known to have a profound influence in both academic study and industrial application of materials. Superhydrophobic surfaces, with a static contact angle higher than 150° and a contact angle hysteresis lower than 10°, have received continued attention for their broad applications, such as self-cleaning, antifogging and frosting, and drag reduction. The continuous development of materials and approaches that used to create superhydrophobic surfaces has led to further exploration of coatings with other desirable properties such as superamphiphobicity, mechanical robustness and thermal stability.

In this work, coatings with super wetting and super anti-wetting properties were designed and fabricated …

Design And Synthesis Of Polymer Brush Surfaces With Complex Molecular Architectures And Morphologies, Wei Guo

Dissertations

The combination of surface-initiated polymerization (SIP) and postpolymerization modification (PPM) is a powerful technique for the fabrication of functional soft surfaces. Better understanding the influence of the aforementioned factors on the PPM effectiveness is valuable for fulfilling the potential of the PPM approach for the fabrication of functional soft surfaces. Specifically, by carefully balancing modification reactivity and limitation of mass transport, polymer brush with composition heterogeneity and gradient along the normal direction of the surface otherwise unattainable by methods of direct polymerization can be fabricated via the PPM approach which opens doors to new routes to polymer brush with complex …

Parameterization Of Ar231453: A Potent Agonist Of The Gpr119 Receptor, A Target For Diabetes Treatment, John E. Hamilton

Theses and Dissertations

The first reported potent agonist for the GPR119 receptor, a potential target for the treatment of diabetes, is 2-fluoro-4-methanesulfonyl-phenyl-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine (AR231453). The dynamic interactions of AR231453 with GPR119 using molecular dynamics simulation are of great interest. However, parameters for AR231453 that describe the behavior of the molecule in the CHARMM force field have not been determined. The following study produces parameters by creating model fragments and compares the produced parameters to quantum calculations. The produced parameters are then further refined within the Visual Molecular Dynamics (VMD) program’s plugin program, the Force Field Toolkit as well as Gaussian 09 and CHARMM. Molecular …

Desorption Electrospray Ionization (Desi) Mass Spectrometric Imaging Of Spatially Regulated In Vivo Metabolic Rates, Charlotte Reininger Lewis

Theses and Dissertations

Desorption electrospray ionization (DESI) is an ambient ionization technique used for mass spectrometric imaging of biological samples. When coupled with isotopic ratio measurements of deuterium-labeled tissues, DESI provides a means of measuring metabolic rates on a spatially resolved basis. In vivo metabolic rates are desired to better understand diseases such as Alzheimer's, Parkinson's, Huntington's, and various forms of cancer that negatively impact metabolic rates within different organs of the human body. Although DESI has been used to image lipids and metabolites of a variety of tissues and other imaging techniques, such as NIMS, have been used to study kinetic turnover …

Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton Iii

Electronic Theses and Dissertations

Mesoporous silica gel containing embedded phosphotungstic acid (PTA) was synthesized by sol-gel co-condensation of tetraethyl orthosilicate with PTA in acidic media. The obtained material had high Brunauer-Emmett-Teller Theory (BET) surface area and pore volume. A characteristic band of the Keggin structure of PTA was present in its FT-IR spectrum while its X-ray diffraction patterns were absent. This proved the embedding of PTA on a sub-molecular level and not as a second phase. Acidic sites were determined by neutralization with base in aprotic solvent, followed by titration of the remaining base with an acid. The material demonstrated high adsorption capacity of …

Part (I): Synthesis, Characterization And Antibacterial Activity Of Vanadium(V) Complexes With Ons Schiff Bases Part (Ii): Synthesis Of 9-Cd₃-11-Cis-Retinal For The Investigation Of The Activation Mechanism Of Gpcr Rhodopsin By Solid-State ²H Nmr Spectroscopy, Samira M. Faylough

Theses and Dissertations

Vanadium compounds are known to play many roles in both biology and industry, and the biochemical activity of these compounds has led to their increased importance in both biological and medical research. In the present work, some new substituents for hydrazinecarbodithioate Schiff base ligands and their dioxo vanadium(V) complexes were synthesized and characterized by ¹H NMR, ¹³C NMR, DART mass, FT-IR, UV-vis, fluorescence spectrometer, and single X-ray diffraction analysis for complex K[VO₂{(S-benzyl-3-(2-hydroxy-5-nitrophenyl) methylene dithiocarbazate)}] (212). Dioxovanadium(V) complexes K[VO₂{(S-methyl-3-(2-hydroxy-5-nitrophenyl)methylenedithiocarbazate)}] (211) and 212 have been tested for antibacterial activity against Burkholderia pseudomallei and Burkholderia mallei strains. Ceftazidime was used as a reference …

Role Of Nanoparticles In Voltammetric Signal Enhancement Exhibited By Layer-By-Layer (Lbl) Gold Nanoparticle-Modified Screen-Printed Carbon Electrodes (Spces), Ben K. Ahiadu

Electronic Theses and Dissertations

Screen-printed electrodes (SPEs) have found wide use as sensing platforms due to their simple fabrication, customizability in terms of geometry and composition, and relatively low cost of production. Nanoparticles have been incorporated in or interfaced with SPEs in order to improve sensor response or provide electrocatalytic capabilities. Though nanomaterial-modified SPEs are becoming increasingly common sensing platforms, the benefits provided by nanomaterials are often determined through voltammetric studies with common redox probes, such as ferricyanide. However, recent reports have documented the ferri-/ferrocyanide redox couple to be an unreliable system for characterizing some carbon-based electrodes due to the dependence of its electrochemical …

Enzyme Kinetics Studies To Guide Mathematical Modeling Of Microdialysis Sampling To Predict In Situ Biochemistry, Justin M. Klucher

Chemistry & Biochemistry Undergraduate Honors Theses

Microdialysis is a diffusion-based sampling method that can be useful for monitoring various biological systems. Matrix metalloproteinases are a class of enzymes responsible for remodeling the extracellular matrix that, when dysregulated, are linked to various diseases. The delivery method of microdialysis is of particular interest as a sampling technique for enzymatic reactions. Microdialysis was performed in vitro using a model enzyme, porcine pancreatic elastase, because it is a useful substitute for matrix metalloproteinases. A colorimetric substrate for elastase, succinyl-ala-ala-ala-p-nitroanilide, and its product p-nitroaniline were measured using a UV-Vis spectrophotometer. Using an expanded Beer’s Law equation, both analytes’ concentrations were determined …

Design And Characterization Of Plasmonic Nanoprobes And Interparticle Interactions For Surface Enhanced Raman Scattering And Biomolecular Detection, Zakiya Skeete

Graduate Dissertations and Theses

Functional nanoparticles serve as an intriguing class of probes in medical theranostics for enabling rapid, sensitive, multiplexing, and point-of-care treatment and diagnosis. One important aspect of these applications is the exploitation of the unique plasmonic properties of certain metal nanoparticles. A key challenge is the understanding of effective harnessing of the plasmonic coupling of the nanoparticles upon interacting with the targeted biomolecular species. This thesis work focuses on investigating the interparticle interactions of chemcially-labled and bioconjugated gold and silver based nanoparticles and their influences on the plasmonic coupling for specctroscopic detection of biomolecules. Examples of the interparticle interactions include dye-mediated …