Chemistry Commons^™

Domain-Specific Probes For Calcium Binding To Neural Cadherin, Charles Ryan Humphries

Honors Theses

Cadherin is a major mediator of cell adhesion whose adhesive function is dependent upon calcium binding. However, the binding of calcium is not completely understood. The binding of calcium can be monitored using an abbreviated construct that contains only the first two extracellular domains (EC12) which includes two tryptophan residues, W2 and W113. Single tryptophan mutants were created which contain only W113 (W2A) and W2 (W113F). Fluorescence spectra were obtained of W2A, W113F, and WT in the presence and absence of calcium. Calcium titration data were collected for each protein. In both experiments, calcium binding increased the fluorescence signal of …

Identification Of A Phytotoxic Fungus And An Investigation Into The Isolation Of Its Phytotoxic Constituents, William E. Briscoe

Honors Theses

A fungus was isolated from Hedera helix (English ivy) leaves experiencing necrosis and identified as Diaporthe eres by molecular techniques. The fungus was grown in potato dextrose broth medium and the culture medium was extracted with ethyl acetate. Bioassay guided fractionation of ethyl acetate extract of culture filtrate of this fungus led to the isolation of two phytotoxic compounds that are active against the seed germination of the monocotyledon Agrostis stolonifera at 1 mg mL-1. Structures of these active compounds were determined by spectroscopic methods and were determined 8-hydroxy-3.7-dimethylisochroman-1-one and 2-(4-hydroxyphenyl)-ethanol. This is the first finding presented on the phytotoxic …

Anchoring The Potential Energy Surfaces Of Homogenous And Heterogenous Dimers Of Formaldehyde And Thiofomaldehyde, Christina M. Holy

Honors Theses

This work characterizes five stationary points of the formaldehyde dimer, (CH2O)2, two of which are minima, seven newly-identified stationary points of the formaldehyde/thioformaldehyde (mixed) dimer, CH2O/CH2S, four of which are minima, and five newly-identified stationary points of the thioformaldehyde dimer, (CH2S)2 , three of which are minima. Full geometry optimizations and corresponding harmonic vibrational frequencies were performed on CH2O and CH2S as well as each of the dimer configurations (Figures 3-5). The computations were carried out with second order Møller-Plesset perturbation theory (MP2), with the heavy-auc-cc-pVTZ (haTZ) basis set. Additionally, thirteen density functional theory methods were employed: B3LYP, B3LYP-D3, B3LYP-D3(BJ), …

The Origins Of An Everyday Behavior: Why Do People Share Meals?, David Lee

Honors Theses

Humans are socially driven creatures that require constant interaction. One way humans have consistently expressed their social nature since prehistory is through sharing meals. Recent studies and literature were examined in order to investigate the roots behind why sharing meals has been the most consistent method of social output. Through careful reading and analysis, reasons behind why people share meals were traced in perspective levels. The biological and molecular aspect explains how humans evolved from prehistoric primates and their similarities associated with food consumption. Genetics and food preferences also play a role by allowing humans to taste food rather than …

Synthesis, Characterization And Electrochemical Properties Of Gold Nanomolecules, Vijay Bhaskar Reddy Jupally

Electronic Theses and Dissertations

Chapter 1 gives a brief introduction to the field of gold nanomolecules. Various synthetic protocols and analytical techniques used through out this dissertation are discussed in detail. Size dependent properties of the gold nanomolecules are described. The structure of gold nanomolecules is explained based on the crystal structure of Au25(SCH2CH2Ph)18. The theoretical basis for the stability of the gold nanomolecules is explained using the super atom complex model and geometric parameters. Chapter 2 includes ligand exchange experiments on gold nanomolecules. Ligand exchange experiments are used to modify the monolayer of nanomolecules after synthesis. Ligand exchange reactions are monitored by mass …

Characterizing Non-Covalent Interactions And Peptide Bond Formation With Electronic Structure Theory, Eric Van Dornshuld

Electronic Theses and Dissertations

The development and application of quantum mechanics has exploded in the past century. The rules of classical mechanics were found to be completely insufficient when applied to a universe that operates on the scale of atomic and subatomic particles. The advancement of quantum theory and computer technology has driven quantum mechanical analyses toward routine in the chemist's laboratory. Chapter 1 briefly outlines some comfailures of classical mechanics from a historical standpoint. Chapter 2 provides a mathematical overview to quantum chemistry including a brief presentation of the analytic solutions to the schrã¶dinger equation for some model systems. Chapter 3 and chapter …

Spectroscopic Analyses Of Factors Affecting Formation And Stability Of I-Motif Dna, Samantha Michelle Reilly

Electronic Theses and Dissertations

The four-stranded i-motif (iM) conformation of DNA has importance to a variety of biochemical systems that include nanomaterials and oncogene regulation. Fundamental studies to understand iM formation and its structure in solution still remain to be done. In this dissertation, we will discuss the use of the fluorescent base analog tC° to determine the structural state of DNA in solution. We will also demonstrate the use of tC° to determine both the hydrodynamic properties and the folding mechanism of an iM. We also determined the loop length dependence on iM formation and stability. Our hydrodynamic studies show that the iM …

The Impact Of Ph On The Structure And Function Of Neural Cadherin, Jared Michael Jungles

Electronic Theses and Dissertations

Neural (N-) cadherin is a transmembrane protein within adherens junctions that mediates cell-cell adhesion. It has 5 modular extracellular domains (EC1-EC5) that bind 3 calcium ions between each of the modules. Calcium binding is required for dimerization. N-cadherin is involved in diverse processes including tissue morphogenesis, excitatory synapse formation and dynamics, and metastasis of cancer. During neurotransmission and tumorigenesis, fluctuations in extracellular pH occur, causing tissue acidosis with associated physiological consequences. Studies reported here aim to determine the effect of pH on the dimerization properties of EC1-EC2 N-cadherin in vitro. Since N-cadherin is an anionic protein, we hypothesized that acidification …

Elemental Fingerprinting Using Inductively Coupled Plasma Mass Spectrometry And Chemometrics: Application To Environmental Science And Provenance Studies, Lorlyn Paquibot Reidy

Electronic Theses and Dissertations

No abstract provided.

Synthesis And Characterization Of A New Bimetallic Catalyst, Gjl-46, And Its Use In The Catalytic Hydrosilylation Of Phenylacetylene, Gabriel J. Labonia

Honors Theses

A new bimetallic catalyst was synthesized from the metalation of 1,1'-(1,3-phenylene) bis(4-butyl-1 H-1,2,4-triazol-4-ium) iodide with silver oxide and the transmetalation of that complex with Rh(COD)2OTf. The structure of the compound, GJL-46, with molecular formula C34H46I2N6Rh2, was confirmed with mass spectra analysis, 1H NMR and 13C NMR. The catalytic activity of the produced molecule, GJL-46, with molecular formula C34H46I2N6Rh2, in the hydrosilylation of phenylacetylene is reported.

Energy Drinks And Caffeine: The Science Behind The Billion- Dollar Industry, Eric Villarreal

Honors Theses

Ask any college student how he or she gets through long study sessions, all-nighters, and the always grueling finals week and he or she will most likely reference some caffeine-containing beverage as the antidote, with energy drinks becoming an ever increasing option. The effects, both physiological and psychological, of the ingredients in energy drinks (caffeine and, to a lesser degree, glucose) dictate their usefulness to consumers. A review of the available research literature from http://scholar.google.com using the following keywords: caffeine, energy drink, Red Bull, caffeinated beverage, caffeine drink, energy drink industry, energy drink company, and glucose yielded the references that …

Non-Covalent Interactions, Dative Bonding, And Electron Affinities: A Multi-Method Computational Study Of Boron Tetrahalides, Lance R. Ezell

Honors Theses

This study focuses on boron tetrahalides of the form BFXClY, where X + Y = 4, using the B3LYP, M06-2X, and MP2 methods with the aug-cc-pVTZ basis set. The various neutral and anionic species were constructed and optimized using the Gaussian 09 software package, and the equilibrium geometries, harmonic vibrational frequencies, and energetics (specifically the electron affinity, vertical attachment and detachment energies, and stability with respect to dissociation) of each system are presented. The anionic species, due to their closed-shell electron configurations, have relatively high symmetry: Td for BF4- and BCl4-, C3v for BF3Cl- and BFCl3-, and C2v for BF2Cl2-. …

An Investigation Into Polyiodination Of Activated Benzene Derivatives With Electrophilic Aromatic Substitution Reactions, Dakota Gilbert

Honors Theses

The aim of this research is to investigate the periodination of benzene derivatives that are activated towards electrophilic aromatic substitution. In this research, a successful electrophilic aromatic substitution reaction was completed with procedures that used iodine with silver sulfate as an activating agent in the reaction mixture. The ball-milling technique with N-iodosuccinnimide as the iodinating reagent was also explored. Only one iodine was added onto 4-iodoanisole as the activated benzene derivative. When 2,4-dichloroanisole was the substrate, a small amount of diiodo product accompanied the monoiodo product, but no triiodo (periodinated) product was observed. Nonetheless, the trials of this research give …

Mercury In Fish In North Mississippi Reservoirs: Statistical Analysis And Risk Assessment, Stacy Wolff

Honors Theses

Mercury (Hg) is a pollutant of particular concern because it is wide-spread, persistent, and poses a serious risk to human health. Once released into the atmosphere, it cycles through the environment by a series of complex biogeochemical processes. Upon deposition to aquatic ecosystems, inorganic mercury can be transformed to methylmercury by microorganisms. Methylmercury is a known human neurotoxin that can bioacculmulate in fish tissue and biomagnify up aquatic food chains. Consumption of contaminated fish is the primary route of human exposure to methylmercury. The Mississippi Department of Health has issued fish consumption advisories for Grenada and Enid Lakes in the …

Investigation Into The Synthesis Of Dodecahydro-3a,9a-Diazaperylene, Andrew Palmer

Honors Theses

Dodecahydro-3a,9a-diazaperylene (DHDAP) may serve as a potential donor for use in a donor-sigma-acceptor complex for unimolecular rectification. In order to use DHDAP as a donor, its synthesis must first be studied and altered in such manners as to add a synthetic handle. Other things of important include increasing the yield and better understanding the mechanism by which DHDAP forms. Numerous experiments were conducted in various manners such as testing various solvents among various temperatures to even adding in extra reagents to push the reaction one way or another. In the end the yield of the synthesis was found to improve …

Studies Of Mercury In Water, Sediment, And Fish In Mississippi: Concentrations, Speciation, Cycling, And Isotopic Composition, Garry Brown

Electronic Theses and Dissertations

The goal of this project is to better understand the biogeochemical cycle of mercury (Hg) in Mississippi to aid those managing the resources and developing related policy. To that end, Hg levels were determined in a total of 202 fish from Enid, Sardis and Grenada Lakes; Enid and Grenada have fish consumption advisories due to Hg. In addition, total-Hg and methylmercury (MeHg) levels were determined in the inflow and outflows from Enid and Sardis Lakes and in bottom sediment and suspended solids in Enid Lake. Potential sources of Hg to Enid Lake were investigated, including precipitation and runoff from urban, …

Synthesis, Characterization And Application Of Pt Complexes With Pincer Ccc-Bis(Nhc) Ligands, Xiaofei Zhang

Electronic Theses and Dissertations

The unique metallation/transmetallation route for the synthesis of CCC-bis(NHC) pincer ligand supported transition metal complexes was extended to Pt. Several platinum complexes were synthesized. The identity of these complexes was confirmed through multiple technologies, including nuclear magnetic resonance spectroscopy, mass spectroscopy, elemental analysis, thermal analysis, and X-ray crystallography. The intriguing photophysical and thermal properties of these complexes are reported. These complexes were believed to be congeners of materials for organic light emitting diodes (OLEDs).

A Raman Spectroscopic Study Of The Effects Of Hydrogen Bonding On 1,2,3-Triazole, Anna Craig

Honors Theses

The goal of this thesis is to analyze the effects of hydrogen bonding on liquid 1H- 1,2,3-triazole. Spectra of neat 1H-1,2,3-triazole are compared to simulated spectra and are found to differ greatly. The experimental spectrum, however, matches the simulated spectra of 1H-1,2,3-triazole dimers very well. This suggests that dimers play a large role in the liquid structure of 1H-1,2,3-triazole. Though tautomerism is thought to play a large role in the vibrational behavior of 1,2,3- triazole, the Raman spectra obtained here suggest that molecular dimers dominate the liquid state much more so than tautomerism. Even in aqueous solution, the simulated spectra …

Spectroscopic Study Of Charge Transfer Induced Blue Shifting Of Pyrimidine/Water Mixtures On Silver Substrate, Annie Katherine Mcclellan

Honors Theses

Surface enhanced Raman spectroscopy (SERS) is a chemical method gaining much popularity in recent years. With the use of a roughened metal surface or metal nanoparticles, surface plasmon resonances enhance the electromagnetic field allowing for increased Raman signal. Pyrimidine, having two lone pairs of electrons, is capable of charge transfer interactions contributing to a SERS chemical enhancement factor as well. It has recently been reported that hydrogen bonding with water results in the blue-shifting of certain normal modes of pyrimidine. By comparing experimental polarized Raman spectra with the results of electronic structure calculations, the origin of this blue-shifting was found …

Early Transition Metal Ccc-Nhc Pincer Complexes: Synthesis, Characterization, And Catalysis, Theodore Rudy Helgert

Electronic Theses and Dissertations

The previously reported amine elimination methodology for the metalation of CCC-NHC pincer ligand precursors has been extended to other early-transition metals and ligands. Specifically, synthetic results for the preparation of imidazole based CCC-NHC pincer Ti (IV), CCC-NHC pincer Ta (V) will be discussed. In addition, the synthesis of a new triazole based CCC-NHC pincer ligand precursor and its metalation with Ta (V) will be presented. Coordination sphere manipulation of the new pincer complexes using TMSCl for the Ti complex and lithium t-butylamide for the Ta complexes is also discussed. The reaction of the initial Ta CCC-NHC complex with lithium t-butylamide …

Method Development Using Laser Ablation And Solution Icpms And Their Application In Environmental Science And Forensic Provenance Studies, Kaixuan Bu

Electronic Theses and Dissertations

Inductively coupled plasma mass spectrometry (ICPMS) is an analytical technique that can be used to determine multiple elements and isotope ratios in a wide variety of samples. In this work, four projects are described that involve the method development using laser ablation (LA) and solution-based ICPMS and their application in environmental science and forensic (provenance) investigations. In the first project, plutonium (Pu) concentrations and 240Pu/ 239Pu atom ratios were measured in kelp, lichen, aquatic moss, and horse mussel collected on or near Amchitka Island, a former nuclear test in Alaska, and at a background site. The Pu in terrestrial and …

Ph Dependent Proteolysis Of Neural Cadherin, Candice Ashton Walters

Honors Theses

Cadherins are the primary calcium-dependent cell-cell adhesion molecule and are essential to vertebrates. They ensure the integrity of epithelial barriers that allow for maintenance of homeostasis in humans and protection against invading microorganisms. A common invader capable of forging past this line of defense is the fungus Candida albicans. The main virulence mechanism of C. alibans in acidic environments is its secreted aspartyl proteinases (SAPs), which are hydrolytic enzymes that degrade cadherin-mediated cell adhesion leading to infection of the underlying tissues. Cadherin is normally resistant to cleavage by proteases due to stabilization of the protein structure by bound calcium and …

Effects Of Micro-Solvation On Room Temperature Ionic Liquids, Joseph Wellington Golden

Honors Theses

Room temperature ionic liquids (RTILs) have received much attention lately. These compounds are made completely of ions and are liquid at or near room temperature. These liquid salts have a number of unique properties that make them an interesting system to study. These properties include almost zero vapor pressure, thermal stability, large liquidus range, etc. Due to these properties and others, ionic liquids (ILs) have attracted much attention in the emerging field of green chemistry as potentially new solvents for many of the hazardous and volatile solvents currently in use. Moreover, the complex interactions of the anion and cation systems …

Optimization And Development Of In Vitro Bioassays To Determine Structure-Activity Relationships For Cannabinoid Receptor 1 And Cannabinoid Receptor 2, Afeef Husni

Electronic Theses and Dissertations

Cannabis has been around for thousands of years and has been used recreationally, medicinally, and for fiber. Over 400 compounds have been isolated from Cannabis sativa with approximately 100 being cannabinoids. Of those 100 compounds, Δ9-THC has been determined as the primary constituent, which is also responsible for the psychoactivity associated with Cannabis. Along with Δ9-THC, cannabidiol has been studied in depth for its therapeutic effects. This has currently been the focus of many researchers since cannabidiol does not cause psychotropic effects.

Cannabinoid receptors belong to the large superfamily of G protein-coupled receptors (GPCRs). Approximately 30% of marketed drugs target …

Elemental And Isotopic Analysis Of Sediments From Oxbow Lakes In The Mississippi Delta, Pragya Chakravarty

Electronic Theses and Dissertations

No abstract provided.

Synthesis And Characterization Of Nickel Complexes With Relevance To Nickel Acireductone Dioxygenase And Nickel Superoxide Dismutase, Margo Nicole Montgomery

Electronic Theses and Dissertations

This research presents an investigation of synthetic model complexes with relevance to the active site of Ni(II) acireductone dioxygenase (Ni-ARD) and Ni(II) superoxide dismutase (Ni-SOD). Acireductone dioxygenases (ARDs) are a unique set of enzymes found in the methionine salvage pathway that catalyze the oxidation reaction of acireductone (1, 2-dihydroxy-3-oxo-5-(methylthio)pent-1-ene). These enzymes share a compolypeptide sequence but bind different metal ions, Ni2+ or Fe2+, at the active site. The Ni-ARD enzyme is responsible for the off pathway shunt in the pathway. Using the tridentate nitrogen donor ligands hydrotris(3,5-dimethyl-1-pyrazolyl)borate (Tp*) and the newly developed tris(1, 2-dimethyl-4-imadozyl)carbinol, (4-TICMe, Me) several reactions involving the …

Theoretical And Spectroscopic Studies Of Molecular Systems For Charge Transfer And Energy Storage And Transfer, Debra Scardino

Electronic Theses and Dissertations

Efficient charge transfer and energy storage and transfer have become increasingly important in many areas of research and development. This is especially true for the development of optoelectronic devices, molecular electronics, and solar voltaic cells. Characterization of the photophysical properties of new molecular systems for these applications has emerged as an important field of research. Many molecular building blocks have been developed and understanding the properties of these systems at a fundamental level is essential for their successful implementation. This dissertation focuses on experimental and theoretical studies of some of these newly-developed molecular systems. Oxygen substituted dihydrobenzvalene is studied theoretically …

On The Nature Of Weak Intermolecular Forces: A First Principles Approach To Hydrogen Bonding And Pi-Type Interactions, Kari Lorene Copeland

Electronic Theses and Dissertations

Computational quantum chemistry is a branch of chemistry that is based on quantum mechanics. In this field, chemical phenomena is represented in mathematical form and computers are used to provide numerical solutions to rigorous mathematical equations. Through this medium, the properties of atoms and molecules are calculated with high accuracy. Chapter 1 opens with a general discussion of science, the development of atomic theory and computational chemistry. Electronic structure theory is more extensively reviein Chapter 2. Hydrogen bonding and dispersion forces are defined in Chapter 3, and the procedures used to computationally study these type interactions are considered. Chapter 4 …

Elucidation Of B-N And B-P Stretching Vibrations Using Raman Spectroscopy And Electronic Structure Calculations, Dana Nicole Reinemann

Honors Theses

Boron-nitrogen (B-N) and boron-phosphorus (B-P) dative bond stretching vibrational frequencies were studied using vibrational spectroscopic methods and electronic structure calculations. There has been a great controversy over the assignment of B-N dative bond vibrational frequencies for many years with a range of inconsistent assignments in the literature. The B-N dative bond stretching frequency in N-methyliminodiacetic acid (MIDA) esters was analyzed here using infrared, Raman, and surface enhanced Raman spectroscopic methods and compared to the results of electronic structure calculations employing the MP2 and M06-2X methods with a triple zeta basis set. The mode including the B-N stretching motion proved to …

Your Body Is A Temple: Type-2 Diabetes In Mississippi And The Potential Role Of The Black Church In Diabetes Education And Intervention, Jonathon Troy Jackson

Honors Theses

Type-2 diabetes and obesity are two major health complications that are affecting many Mississippians, namely the African American population. A substantial amount of research has been conducted that explains the high prevalence rate of type-2 diabetes and obesity in the African American community as partially due to many secondary factors, including the Southern cuisine, food scarcity, physical inactivity, and poverty. Recently, efforts to reach the African American population about diabetes education and prevention in other Southern states have been directed to faith-based organizations. Researchers have hoped that faith-based intervention might be better suited at helping a wider audience in a …