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 …

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 …

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 …

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.

The Effects Of Structural Modification Of The Wing Helix Domain Of Pria On Bacterial Dna, Erich Auer

Honors Theses

During a cell’s life it must copy itself or face death. For the cell to form a new copy it must replicate its DNA, this DNA is the blueprint for the essential components of the cell. The replication process does not always go to completion, which is necessary for the cell to survive, so there are mechanisms to keep the replication process running smoothly. In bacteria, PriA is used to restart replication after damage to the DNA. By looking at the structure of PriA we can start to determine how exactly it works with the damaged DNA and restart the …

Synthesis Of Bis(Quinoxalino) Ligand For The Removal Of Transition Metal Contamination, Alexander J. Farmer

Honors Theses

Transition metal contamination is a constant concern both in the environment and in chemical reaction mixtures. One proposed solution, is the use of peraza-crown macrocycles to selectively bind and remove transition metals. The aim of our project is to determine the novel synthesis of bis(quinoxalino) peraza-crown macrocycles for use as ligands to bind to transition metals. Our proposed molecules incorporate the rigid quinoxaline subunit into an aza-crown macrocycle which can improve binding properties. The synthesis route is novel and overcomes several limitations of the existing methods of aza-crown macrocycle preparation. We have designed the synthesis in such a way that …

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.

Preparation, Analysis And Derivatization Of Benzotris(Thiazole) Triamine, Jonathan Patrick Peter Alessi

Honors Theses

Multiple fields are areas of active research where organic materials hold considerable promise, such as thermoelectrics or photovoltaics. In an effort to design and prepare a new system which would exhibit a set of promising features such as high thermal stability, high degree of planarity, rigid skeleton and strong electron accepting properties, we have undertaken the preparation and characterization of benzotrithiazole and its derivatives. Our work has led to a reproducible and scalable protocol for the generation of one particular structure: benzo[1,2-d:3,4-d':5,6-d"]tris(thiazole)-2,5,8-triamine. We have also conducted further attempts to functionalize this structure, leading to other derivatives of the target compound.

A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel

Honors Theses

Nitrogen (¹⁵N) isotope tracer studies are an invaluable tool for understanding the rate of N transformations in the environment. A mechanistic understanding of N cycling is critical to management of excess N availability in freshwater and marine ecosystems. Conventional methods for measuring ¹⁵N:¹⁴N of dissolved inorganic nitrogen species are time consuming and require large sample volumes. Here, we present a technique for measuring ¹⁵N:¹⁴N in ammonium (NH₄⁺) using electrospray ionization mass spectrometry (ESI-MS). NH₄⁺ present in small volumes of sample (3 ml) is complexed with phenol via …

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 …

Investigating Medicinally Important Portein-Protein And Protein-Ligand Interactions : A Computational Approach, Cooper Ashley Taylor

Honors Theses

Molecular dynamics (MD) simulations and computational chemistry allow for an atomistic understanding of protein-protein and protein-ligand binding motifs. Through the use of MD, medicinally relevant complexes can be examined in detail unattainable by experimental methods. Within this work, systems pertinent to both Alzheimer’s Disease and HIV-1 are probed and thoroughly sampled to help elucidate potential therapeutic pathways. We used molecular dynamics and free energy estimations to gauge the affinity for the binary and ternary complexes of KLC1, APP and JIP1, three proteins all believed to be involved in the propagation of Alzheimer’s Disease. Two areas of thought exist suggesting that …

An Analysis Of The Acid Profile Of Coffee Brews: Caffeine And Chlorogenic Acid Concentrations In Different Forms Of Coffee Brew, Jeffory Taylor Wallace

Honors Theses

In this project, different coffee brews were analyzed in order to determine the effects the brewing method had on the final product, particularly the acid profile of the final product. Our hypothesis is that the use of a cold brewing method will produce different amounts of caffeine and chlorogenic acids in the final brewed product compared to traditional hot brewing methods. There are many brewing methods available. For the purposes of this research, three were chosen and one was created. The three chosen methods were: a traditional drip brew, a cold brew, and a Pezzetti espresso brew. The final method …

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 …

An Analysis Of Stimuli Responsive Biomaterials Using Raman Spectroscopy And Computational Studies, Gretchen Harknett

Honors Theses

This thesis involves the computational and spectroscopic exploration of the linear dendritic block copolymer, poly(L-lactide)-poly(amido-amine), (PLA-PAMAM), under different environmental conditions using Raman spectroscopy, in hopes to utilize it in future effective and cost-efficient drug delivery systems. Janus dendrimers, a material made up of two different dendrimer portions, are currently being studied in great detail, as they possess many attractive features for materials scientists looking to develop ways for drugs to be delivered in more efficient manners than currently available to physicians. The instrumentation used to conduct this thesis is a high resolution Raman spectrometer. Computationally, Gaussian 09 was employed to …

Platelet-Derived Microparticles And Their Role In Sepsis, Robert Tramel

Honors Theses

Causing at least 215,000 deaths in the U.S. annually- more than prostate cancer, breast cancer, and AIDS combined- and rising, sepsis is one of the most deadly medical conditions in America. Sepsis pathophysiology, however, is still incompletely understood, making it difficult for physicians to diagnosis and treat effectively. Given the time-sensitivity of treatment, researchers are now searching for new methods to identify sepsis early, developing more accurate prognostic markers, and developing new target therapeutic candidates. One biological component of interest in this research is the platelet-derived microparticle (PMP), a heterogeneous vesicle derived from the cell membrane of platelets found circulating …

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 …

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 …

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 …