Physical Sciences and Mathematics Commons^™

Prep-Hplc Method Development To Isolate Potentially-Carcinogenic, Arginine-Based Heterocyclic Amines, Victoria S. Kim

Honors Theses

Heterocyclic amines (HCAs) are carcinogenic molecules generated from the reaction of creatin(in)e and amino acids at high cooking temperatures in meat. Previous research has shown that replacing creatine with arginine leads to new, uncharacterized HCA molecules. This research entails implementing and optimizing the preparative HPLC analysis of extracts from multiple burnings of arginine with phenylalanine. Isolated fractions from the prep-HPLC analysis were further analyzed using the Ames test to identify mutagenic compounds. Prep-HPLC provides quality control to the burning process along with isolation of larger quantities of materials for further characterization and molecular structure identification.

Developmental Steroids And Vitamins: Identified And Quantified In Predatory Lady Beetles, Andrea Hixson

Honors Theses

Autumn brings ladybeetles into homes to seek shelter during the winter, which is a nuisance. Their bites may induce an allergic reaction resulting in painful rashes. Predatory ladybeetles have been used as a biological control agents. Not only do they feed on ecological pests, they also feed on the saps of ripe fruits reducing the value of the damaged crop. Two species of ladybeetles (Coleoptera: Coccinellidae) will be examined to determine the quantities of steroids and vitamins used throughout their life stages. The species examined are native, Hippodamia convergens, of North America, and an invasive, Harmonia axyridis, of Asia. The …

The Clean Air Act And Its Impact On Ground Level Ozone Pollution Levels In Los Angeles, California, Rebecca G. Ford

Honors Theses

Ozone (O₃) occurs naturally as a protective, ultraviolet radiation-shielding “Ozone Layer” in the Stratosphere and as a photochemically produced pollutant in the Troposphere. The Clean Air Act (CAA) of 1970 regulates the emission and concentration of O₃ and five other atmospheric pollutants. Since the signing of the CAA, the ongoing question has been whether or not the National Ambient Air Quality Standards (NAAQS) and regulatory policies have had an effect on decreasing O₃ concentration. The Los Angeles metropolitan area is a prime example of how O₃ can be a public health hazard, and taint a …

Octahedral Ruthenium(Ii) Complexes For C-H Bond Activation And Olefin Hydroarylation, Patrick Z. Zdunek

Honors Theses

The study of inert C-H bond activation of hydrocarbons has been gaining interest. As these hydrocarbons are used in the production of many consumables such as fuel, plastics, and detergents, it is necessary to efficiently utilize the finite quantity of petroleum feedstocks. Transition metal complexes are incorporated as catalysts into synthetic routes to create new C-X (X = C, N, O) bonds in order to increase the chemical value of organic molecules. The complex [Ru(η6-p-cymene){P(OCH2CF3)3}(Ph)(OTf)] (1) (P{OCH2CF3}3 = tris(2,2,2-trifluoroethyl) phosphite, Ph = phenyl, OTf = trifluoromethanesulfonate) was prepared and tested for functionality as a catalyst in olefin hydroarylation. Catalytic reactions …

Comparative Analysis Of Drosophila Athabasca Cuticular Hydrocarbons For Generation Of Synthetic Material To Study Evolutionary Implications, Brittany Gay

Honors Theses

Cuticular hydrocarbons (CHCs) have been studied extensively and their roles explored for various species of insects. However, only a single reported study has focused on the role of CHCs in Drosophila athabasca, a species of fruit fly native to North America. The work herein describes advances in identification, synthesis and quantification of biologically relevant CHCs present in this species. Identifying CHC profile differences among D. athabasca sub-races (Eastern A, Eastern B and WestNorthern) was performed using multiple analytical techniques. Synthesis of proposed structures confirmed their identity. External standard curves were used to quantify CHCs. GC-MS analysis of CHCs from several …

A Systematic Investigation Of The Effects Of Chain Length And Ionic Head Group On Perfluoroalkyl Acid Binding To Human Serum Albumin, Jake Ulrich

Honors Theses

Perfluoroalkyl acids (PFAAs) are industrial chemicals used in everyday products ranging from non-stick coatings to fire-fighting foam. PFAAs are contaminants of emerging concern (CECs) and are bioaccumulative, persistent and toxic. Unlike other CECs, PFAAs bioaccumulate in areas of high protein concentration, such as the kidneys, liver and blood; therefore, it is vital to study PFAA-protein interactions. Human Serum Albumin (HSA) is the model protein used for PFAA-protein studies because it is the most abundant protein in the human body and it binds and transports endogenous and exogenous ligands. Previously, researchers have investigated PFAA-HSA binding, but most of these studies have …

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 …

Pine Needle Pyrolysis: Bio-Waste Into Biofuel, Alexandra Fuentes

Honors Theses

This project explores the alternate uses of biomass. In particular it focuses on pine needles as a source for biofuels. Pine needles are of interest because in certain Mountain communities they are collected and removed from residential properties. By removing the pine needles, communities create a “defensible space” to prevent wild fires from destroying homes and property. These needles are often placed in regional landfills. The South Tahoe Refuse and Recycling Services alone has more than 4,340 tons of pine needles dumped at their facility annually. This large amount of biomass can be a potential energy source.

The focus of …

Synthesis Of A Thermally Reversible Cross-Linked System Using Electrophilic Cleavage/Functionalization Of Poly(Isobutylene-Co-Isoprene), Savannah H. Steadman

Honors Theses

Multifunctional polyisobutylenes (PIBs) are of great academic and commercial interest. Current methods to create these materials currently utilize prohibitively expensive synthetic strategies. Recently, Storey et al. reported a novel method for the synthesis of multifunctional PIB which is more commercially viable than the current methods. For this research, the material produced via this technique was utilized to create a thermally reversible crosslinked system using Diels-Alder chemistry. To achieve this, a bromide-functional polyisobutylene obtained via electrophilic cleavage and functionalization of butyl rubber was split into two portions and further functionalized. The first portion of the bromide-functional PIB was reacted with furfuryl …

Characterization Of Epoxy/Amine Networks With Glycidal Polyhedral Oligomeric Silsesquioxane Surface Modified Silica Nanoparticles, Reese K. Sloan

Honors Theses

Silica nanoparticles were surface modified with octa-functional glycidal polyhedral oligomeric silsesquioxane (G-POSS) and incorporated into an epoxy/amine system in an effort to increase the mechanical performance of the inorganic/organic hybrid material. The silica nanoparticles were first functionalized with 3-aminoprpyltrimethoxysilane (APTMOS) at 5 and 10 weight percent, and then modified with G-POSS at ratios of 1:10 and 1:5 (APTMOS: G-POSS). The modified particles were then incorporated into an epoxy/amine network consisting of diglycidyl ether of bisphenol A (DGEBA) and aromatic amine, diamine diphenyl sulfone (4,4’ DDS) at 1 and 5 weight percent, resulting in 8 different formulations. The incorporation of the …

Kinetic Study Of Conjugated Polymer Packing And Agglomeration, Skye R. Travis

Honors Theses

Although organic electronic materials are flexible, cheap to fabricate, and molecularly tunable, their performance has generally been less efficient than that of their inorganic counterparts. Chemical doping has been attempted as a method to increase the efficiency of organic materials. During this process, an organic material, typically a conjugated polymer, is exposed to an oxidant/reductant, called a dopant. Electron transfer between host polymer and dopant molecules increases the charge carrier density in the doped host material, making it a more efficient conductor. The effects of doping using 2,3,5,6-tetrafluoro-tetracyanoquinodimethane (F4TCNQ) on low molecular weight poly(3-hexylthiophene-2,5-diyl) (LMW P3HT) in varying ratios of …

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 …

Extraction Studies Of Toxic Multiply Charged Oxoanions From Aqueous Media Using Nanojars, Hartman Christian

Honors Theses

In this paper, the potential of nanojars as extracting agents of chromate and arsenate from aqueous media into a non-polar organic medium is investigated. Nanojars are a class of compounds that consist of multiple [cis-CuII(μ-OH)(μ-pz)]n cyclic polymerization isomers (n = 6, 8, 9, 10, 12, 14; pz = pyrazolato anion) that form from self-assembly reactions around a multiply-charged oxoanion core with capping counterions to render an overall neutral complex. This incarcerates the anion, preventing it from escaping the complex without the use of any covalent bonding, making it a potentially highly effective and unique extracting agent. We have concluded that …

Molecular Mass Of L-Arginine-Based Potentially Carcinogenic Heterocyclic Amines, Irene S. Hwang

Honors Theses

Investigation of cancer-inducing molecules in cooked foods has led to the discovery of mutagenic heterocyclic amines (HCAs) in meat. The amino acids creatin(in)e and L-phenylalanine form the precursors for these HCAs. Recent research here at Andrews University have found similar mutagenic HCAs produced from plant-based proteins when L-arginine, rather than creatin(in)e, is substituted in high temperature reactions (simulated cooking) with L-phenylalanine. Our research focused on developing HPLC methods to isolate individual candidates that are then screened for mutagenicity via the Ames test. Mass spectroscopy methods were also developed to identfy the molecular structure of these lead mutagenic L-arginine-based HCAs.

Fluorescence Analysis Of Pamam Dendrimers, Ansel Nam

Honors Theses

Despite their lack of conjugation, polyamidoamine (PAMAM) dendrimers are intrinsically fluorescent, and this fluorescent is somewhat manipulable through altering the dendrimer's solvent. This level of fluorescence is dependent on a number of the dendrimer's qualities: the pH of the solvent, the mass percent concentration of the dendrimer in solvent, and the generation size of the dendrimer. In past studies, fluorescent intensity increased as generation size increased and pH decreased. Thus, this research project will attempt to replicate those results as well as further analyze the efficiency of fluorescence of PAMAM dendrimer in comparison to fluorescein.

Synthesis Of Β-Methyl-L-Cysteine As A Model For A Β-Methyl-D-Cysteine Building Block For Incorporation Into Microbisporicins, Elora C. Doskey

Honors Theses

No abstract provided.

Tying The Knot: Applications Of Topology To Chemistry, Tarini S. Hardikar

Honors Theses

Chirality (or handedness) is the property that a structure is “different” from its mirror image. Topology can be used to provide a rigorous framework for the notion of chirality. This project examines various types of chirality and discusses tools to detect chirality in graphs and knots. Notable theorems that are discussed in this work include ones that identify chirality using properties of link polynomials (HOMFLY polynomials), rigid vertex graphs, and knot linking numbers. Various other issues of chirality are explored, and some specially unique structures are discussed. This paper is borne out of reading Dr. Erica Flapan’s book, When Topology …

Photophysical Characterization Of Newly-Synthesized Emissive Materials, Rachael Abigayle Nelson

Honors Theses

One key element in chemistry is understanding the chemical properties of a molecule so that its interactions with itself, other atoms or molecules, or its environment is well known. This knowledge alone allows the chemist to innovate and invent and thereby change the world. Light surrounds and sustains our lives; thus it is vital to understand how light interacts with common and newly synthesized materials. In this thesis the photophysical properties of newly synthesized materials will be discussed to give an overview of the many ways in which light interacts with the chemical materials composing our everyday lives. General photophysical …

Gold And Alloy Nanomolecules: Synthesis, Ligand Induced Core Conversion, Characterization, And Atomic Structure, Shevanuja Theivendran

Honors Theses

Gold nanoparticles have wide range of applications in the field of sensing, imaging, cancer therapy, and other biomedical applications. It is desired to have monodisperse and atomically precise gold nanoparticles to have better control and effective utilization of that nanoparticle. The nanoparticles that are less than 2 nm in size with precise number of atoms and ligands (± 0 atoms) which exhibit unique physical, chemical and optoelectronic properties are called as gold nanomolecules. This thesis presents the synthetic methodology and isolation of various monodisperse atomically precise nanomolecules and their characterization. UV-vis spectroscopy, Electrospray Ionization Mass Spectrometry (ESI-MS), Matrix Assisted Laser …

Modification Of Panobinostat To Increase Its Therapeutic Potential To Cure Multiple Myeloma, Sweta Adhikari

Honors Theses

Panobinostat is a potent histone deacetylase inhibitor that can impede function of a wide range of zinc-dependent histone deacetylases. Panobinostat is the first approved histone deacetylase inhibitor for the treatment of multiple myeloma, along with other drugs such as Velcade and Dexamethasone. Simplistically, it helps to shrink or eradicate tumor growth in multiple myeloma patients. However, the treatment has severe adverse effects due to its lack of selectivity. In collaboration with Dr. Shana Stoddard (Rhodes College, Memphis TN) and Fatima Rivas (St. Jude's Research Hospital, Memphis TN), our research aims to design a more selective model of panobinostat that binds …

A Raman Spectroscopic And Computational Study On The Effects Of Electron Withdrawing Groups On Halogen Bonding, Katelyn Allen

Honors Theses

Here, the effects of individual electron withdrawing groups on halogen bond strength are investigated using Raman spectroscopy and electronic structure calculations. Halogen bonding is a unique and relatively unexplored noncovalent interaction that has recently garnered considerable attention due to its applications in materials development. When a halogen, such as chlorine, bromine, or iodine, accepts electron density from a Lewis base such as the nitrogen of pyridine a halogen bond arises. The anisotropic distribution of electron density about a covalently bound halogen, also known as the σ-hole, plays a significant role in halogen bond formation. The magnitude of the electropositive region …

Iodination Of 3,5-Dichloroanisole Using Silver Salts, Alex Fan

Honors Theses

A paper published by Joshi et al. showed lower than expected yields in mono- and di-iodination of 3,5-dichloroanisole in dichloromethane using silver salts. One possibility for this could be that the starting material was being tri-iodinated and precipitating out of the solution. We used similar reaction conditions in attempts to prepare and isolate triiodinated product, but attempts of recrystallization from ethanol, DMSO, and 2- methoxyethanol showed no signs of it. Removal of silver iodide from the solids formed during the reaction using aqueous potassium iodide resulted in complete dissolution of the entire crude product, suggesting no organic product as well. …

A Study Of The Hydrophobic Interactions Between Twenty-Three Cb1 Selective Jwh Compounds And An Active-State Cb1 Receptor Model To Discover Key Structural Features Of The Jwh Compounds And Key Protein Residues Of The Cb1 Receptor, Lyncyn Louise Reliquias

Honors Theses

Synthetic cannabinoids, commonly found in Spice, have recently become a popular substitute for marijuana as they have similar effects to THC, the most powerful constituent of marijuana. Additionally, they are increasingly becoming a source of drug abuse as they cannot be detected with normal drug test screenings. This study specifically analyzed a total of twenty-three CB1 selective JWH compounds and their hydrophobic interactions with an active-state CB1 receptor model. The ligands were categorized per their structural similarities, and this study was aimed to find patterns within each structural moiety that would lead to the discovery of key structural features and/or …

Cytotoxicity Assay Of Self-Assembling Protein-Based Biomaterials, Peyton Vaughan

Honors Theses

Acute inflammation is a natural biological defensive response against infection,irritation, and injury. While inflammation is a natural process, chronic tissue inflammation has been implicated in the development of several different diseases. With the intent of minimizing collateral damage associated with long-term exposure of healthy tissues to anti-inflammatory drugs, the Pedigo laboratory has designed a system for the self-assembly of protein polymers as scaffolds for controlled-release of drugs to affected tissues. This protein polymer comprises two essential components, with the first component being the calcium-dependent protein, calmodulin, and the second being a corresponding binding peptide, M13. Because Calmodulin has a specific, …

Towards The Synthesis Of A Polyamine Perylenebisimide Derivative For Intercalation Into Quadruplex Dna, Bobby May

Honors Theses

Perylenebisimide intercalation in G-quadruplex DNA is an area of study that has increasing interest in cancer research. The ability of perylenebisimides to interrupt the structures of the G4 DNA on the end of telomeres has allowed for the observation of how the variable-regions of the perylenebisimide can have differing effects on anticancer properties. The purpose of this experiment was to synthesize a perylenebisimide with the intentions of observing its intercalating properties with G-quadruplex DNA. In order to accomplish this, dibenzylamine was substituted onto chloroacetonitrile through an SN2 reaction to produce 2-(dibenzylamino)acetonitrile. The 2-(dibenzylamino)acetonitrile was then reduced with LAH to yield …

Isolation And Identification Of Bioactive Constituents Of Plant Pathogenic Fungi And Targeted Synthesis Of Isochromanone Analogs, Brandon Clausen

Honors Theses

An unknown fungal species was cultured from necrotic Brachiaria eruciformis leaves found in Oxford, Mississippi. The fungus was identified via molecular techniques as Pyricularia grisea. This fungus was grown on Czapek Dox broth culture medium for 21 days under continuous light at 24 0C. The culture filtrate was extracted with ethyl acetate and concentrated. The major bioactive compound, namely pyrichalasin H, was isolated using TLC-guided fractionation and identified via spectroscopic techniques. The compound was then tested for bioactivity on monocotyledons, dicotyledons and agriculturally important fungal species. Cellular leakage, chlorophyll content and root/shoot length bioassays were also performed to probe the …

Hinge Sequence Elements In Epithelial Cadherin Form And Function, Jessica Elizabeth Barnett

Honors Theses

Cadherins play the vital role of mediating cell-cell adhesion in properly functioning tissues of the human body. Malfunction of these adherent cells can lead to drastic consequences like cancer metastasis. Thus, it is imperative to ensure the functionality of the molecular mechanism that drives these adhesive interactions. Of the various types, our studies specifically focused on the structure and function of the 'hinge region' in epithelial cadherin. This 'hinge region', composed of amino acid residues C9, P10, and E11, was of particular interest because it is the site of strand-swapped dimerization. The residues P10 and E11 are conserved within the …

Raman Spectroscopic Studies Of Novel Gold-Containing Nanomaterials, Lemuel Shui-Lun Tsang

Honors Theses

The thiolate-protected gold nanocluster (AuNP) Au38(SCH2CH2Ph)24 was studied using Raman spectroscopy with particular attention to the vibrational modes of the gold-sulfur interface. Such studies of AuNPs are non-trivial, as these materials are weak scatterers that burn and fluoresce readily. Previous works have successfully studied this class of materials using a rolling circle filter to subtract fluorescence backgrounds, but we set out to develop a method which would suppress fluorescence using more fundamental means. For Au38(SCH2CH2Ph)24, it was found that data acquisition was most effective using lower-energy excitation wavelengths, which could be predicted based on the UV-Vis absorption spectrum of the …

An Integrative Synthetic, Spectroscopic, And Computational Study Of The Free Radical Chlorine Dioxide And Its Interactions With Hydrogen Bonded Networks, Sarah C. Sutton

Honors Theses

The free radical chlorine dioxide (ClO2) is a strong oxidizing agent that is used to purify drinking water and medical equipment. The existing literature shows discrepancies in the explanation of the solvent dependent properties of ClO2. The following thesis investigates these properties by integrating integrates inorganic synthesis, spectroscopic analyses, and computational methods. ClO2/water hydrogen-bonded networks were computed with the DFT method B3LYP with 6-31G(d,p) and 6-311++G(2df, 2pd) basis sets. Raman frequency computations were performed on local minima geometries. Experimental Raman spectra of chlorine dioxide solvated in water and methanol were obtained, and the fundamental symmetric stretch (nu1) of each spectrum …