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A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski

Masters Theses

"Alpha hydroxy acids (AHAs) - carboxylic acids with a hydroxyl substitution on the alpha carbon are an important class of molecules. Hydroxy Methyl Thiobutanoic Acid (HMTBA) is an α-hydroxy analog of essential amino acid methionine; it finds extensive use as a feed supplement for avian and bovine species. Efficacy of alpha hydroxy acid uptake is important for nutritional studies and such studies rely on accurate and precise methods for determination of these chemicals in biological samples. Several methods for AHAs determination have been reported, however, the methods are tedious, requiring multiple sample preparation steps. Experiments reported in this thesis were …

Synthesis And Antimicrobial Evaluation Of Novel Di-Triazoles And 4-Arylidene Amino 4,5 Dihydro-1h-[1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

A series of novel di-[3(thiophen-2-yl-methyl)-4,5-dihydro-1H- [1,2,4]triazole-5-one-4yl]n-alkanes (2a-h) were obtained by the reaction of N'-1-ethoxy-2-thiophen-2-yl-ethylydene hydrazino carboxylic acid ethyl ester (1) and diamines. Compound 3 was reacted with aldehydes and 4-(arylidene-amino)-3-thiophen-2-yl-methyl-4,5-dihydro-1H-[1,2,4] triazole-5-ones (4, 5, and 8) with Schiff base character were synthesized. (4-(arylidene-amino)-5-oxo-3-thiophen-2-yl-methyl-4,5- dihydro-1H-[1,2,4]triazole-1-yl)-acetic acid ethyl esters (6, 7, and 9) were obtained by the reaction of 4-(arylidene-amino)-3-thiophen-2-yl- methyl-4,5-dihydro-1H-[1,2,4]triazole-5-ones (4, 5, and 8) and ethyl bromoacetate. The structures of the new compounds were inferred through IR, ^1H/^{13}C NMR, elemental analyses, and mass spectral data. Compound 8i was characterized by IR, ^1H/^{13}C NMR, elemental analyses, mass, and X-ray spectral techniques. Geometry optimization …

Determination Of Iridoid Glycosides From Four Turkish Lamium Species By Hplc-Esi/Ms, Funda Nuray Yalçin, Duygu Kaya, İhsan Çaliş, Tayfun Ersöz, Erhan Palaska

Turkish Journal of Chemistry

An HPLC-ESI/MS method that enables fast detection and identification of iridoid glycosides is described. Eleven iridoid glycosides known to occur in the genus Lamium-lamalbide, sesamoside, 6-\beta-OH ipolamiide, shanzhiside methyl ester, dehydropenstemoside, barlerin (= 8-O-acetylshanzhiside methyl ester), 6-O-syringyl-8-O- acetylshanzhiside methyl ester, lamerioside, lamiide, eriobioside, and ipolamiide, were identified by means of their retention time and ESI/MS data. This method was successfully applied to the identification of the iridoid composition of the n-butanol extracts of Lamium eriocephalum Bentham subsp. eriocephalum, L. garganicum L. subsp. pulchrum R. Mill, L. garganicum L. subsp. laevigatum Arcangeli, and L. purpureum L. var. purpureum from the Turkish …

The Application Of Lc-Ms Technologies For The Detection Of Triazine Herbicides In Water, Michael Cahill

Theses

The triazine herbicides, including, simazine (6-chloro-N,N’-diethyl-1,3,5-triazine-2,4- diamine), atrazine (2-chloro-4-ethylamino-6-isopropylamino-l,3,5-triazine) and cyanazine were developed as selective weed killers. Their design function is to disrupt the photosynthesis of broad-leafed plants. In the intensive production of grasses (e.g. wheat, cereals, etc.) broad-leafed plants growing in the grass production area are economically costly, competitors with the grasses for nutrients; their removal is facilitated by triazines herbicides and simazine and atrazine are the predominant compounds used. Significant amounts of triazine herbicides are consumed by the agricultural industry each year. However, due to the indiscriminate use of pesticides/herbicides, traces of herbicides have been found in run-off …

Methods Development In Qualitative And Quantitative Proteomics, Ting Liu

University of Kentucky Doctoral Dissertations

Proteomics based on liquid chromatography coupled to mass spectrometry has developed rapidly in the last decade and become a powerful tool for protein mixtures analysis. LC-MS based proteomics involves four steps, sample preparation, liquid chromatography, mass spectrometry and bioinformatics. Improvements in each step have extended its applications to new biological research areas. This dissertation mainly focuses on method developments in both qualitative and quantitative proteomics.

The first part of this dissertation focuses on qualitative analysis of T. gondii Parasitophorous Vacuole Membrane (PVM) proteins, which is very important for T. gondii’s survival. The hypothesis of this study is that proteomic …

Absorption Spectral Slopes And Slope Ratios As Indicators Of Molecular Weight, Source, And Photobleaching Of Chromophoric Dissolved Organic Matter, John R. Helms, Aron Stubbins, Jason D. Ritchie, Elizabeth C. Minor, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

A new approach for parameterizing dissolved organic matter ( DOM) ultraviolet-visible absorption spectra is presented. Two distinct spectral slope regions ( 275-295 nm and 350-400 nm) within log-transformed absorption spectra were used to compare DOM from contrasting water types, ranging from wetlands (Great Dismal Swamp and Suwannee River) to photobleached oceanic water ( Atlantic Ocean). On the basis of DOM size-fractionation studies ( ultrafiltration and gel filtration chromatography), the slope of the 275-295- nm region and the ratio of these slopes (S_R; 275-295- nm slope : 350-400- nm slope) were related to DOM molecular weight ( MW) and …

Methods In Industrial Biotechnology For Chemical Engineers, Florentin Smarandache, W.B. Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

Industrial Biotechnology is an interdisciplinary topic to which tools of modern biotechnology are applied for finding proper proportion of raw mix of chemicals, determination of set points, finding the flow rates etc., This study is significant as it results in better economy, quality product and control of pollution. The authors in this book have given only methods of industrial biotechnology mainly to help researchers, students and chemical engineers. Since biotechnology concerns practical and diverse applications including production of new drugs, clearing up pollution etc. we have in this book given methods to control pollution in chemical industries as it has …

Novel Approach For Synthesis Of 2:1 Permethylated Β-Cyclodextrin–C60 Conjugate, Zhu Guan, Yali Wang, Yong Chen, Yongmin Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

Amphiphilic cyclodextrin–fullerene conjugates have potential biological activity, due to their water solubility. In order to study the influence of the linker of these conjugates on solubility and aggregation, a permethylated β-cyclodextrin–C₆₀ conjugate with a short linker –(CH₂)₂NHCO–, which is attached to the secondary face of β-cyclodextrin was synthesized. Its solubility in water and its UV spectrum in CH₂Cl₂ and water were investigated.

Design And Synthesis Of Small-Molecule Inhibitors As Anti-Malarial And Anti-Serpin Agents, Maria Mirela Puscau

Master's Theses and Doctoral Dissertations

This work describe the design, synthesis and evaluation of small-molecule inhibitors of two different biological targets: Plasmodium falciparium, the most virulent malarial parasite in humans, and plasminogen activator inhibitor-1 (PAI-1), an endogenous serine proteases inhibitor implicated in a wide range of biological processes. Malaria is one of the top global health threats, and there is a great need for developing effective new chemotherapies. PAI-1 is a major component in the regulation of the plasminogen activation system, and the overexpression of this protein has been implicated in a number of conditions, such as thrombosis, atherosclerosis, and myocardial infarction. The research …

Laser Surface Thermal Lensing (Stl): An Optical Method For Surface Analysis Of Glass Transition Effects In Transparent Polymers, Nandita Prasad

Master's Theses and Doctoral Dissertations

Absorption of energy from a modulated laser beam by a transparent substrate leads to cyclic thermal expansion and contraction of the surface at the pump beam focus. This minute distortion of the surface forms a transient optical lens structure, which can be monitored by the changes it induces in a second laser beam reflected at an angle off the same focal point. The Surface Thermal Lensing (STL) technique is based on detecting the modulated interference pattern that results from interaction of the probe beam wavefront as it reflects from both the flat surface surrounding the transient lens and the curved …

Application Of Impedance Spectroscopy To The Study Of Dithiocarbamate Species On Au Surfaces: Effects Of Aqueous Cu²⁺ And Mg²⁺ Ions, Tom Riha

Master's Theses and Doctoral Dissertations

Self-assembled monolayers (SAM) of dithiocarbamate ligands were formed on the Au surface of an interdigitated electrode (IDE) array by reaction of amines with CS₂ in H₂O/CH₃OH solutions. Impedance spectroscopy was used to probe for the presence of each SAM as they were individually applied to the surface of the IDE by examining differences in collected impedance data after each step of the chemical application sequence. The impedance behavior of the SAM’s were then studied in the presence of aqueous Cu²⁺ and Mg2+ ions. A treated IDE array would, in theory, be able to preferentially …

Should I Stay Or Should I Go? Eukaryotic Translation Initiation Factors 1 And 1a Control Start Codon Recognition, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

Start codon selection is a key step in translation initiation as it sets the reading frame for decoding. Two eukaryotic initiation factors, eIF1 and eIF1A, are key actors in this process. Recent work has elucidated many details of the mechanisms these factors use to control start site selection. eIF1 prevents the irreversible GTP hydrolysis that commits the ribosome to initiation at a particular codon. eIF1A both promotes and inhibits commitment through the competing influences of its two unstructured termini. Both factors perform their tasks through a variety of interactions with other components of the initiation machinery, in many cases mediated …

Mutation Of The NΖ-Carboxylated Lysine Of Oxa-1 Β-Lactamase Results In Deacylation Impaired Enzyme And Build-Up Of Acyl-Intermediate, Kyle D. Schneider, David A. Leonard

Student Summer Scholars Manuscripts

β-lactamases hydrolyze penicillin, cephalosporin, and carbapenemβ-lactam antibiotics. The class D β-lactamase OXA-1 has a catalytic serine (position 67) thought to be deprotonated and thereby activated by an unusual N^ζ-carboxylated lysine (position 70). We have made several mutations of OXA-1 at both K70 and S67 to help elucidate the role of these two critical residues in the catalytic mechanism. We have used the fluorescent substrate BOCILLIN FL to demonstrate that the K70 mutants can acylate but are severely impaired for deacylation of various substrates. Interestingly, deacylation rates vary depending on the identity of the substituting residue, from t_{1/2 …}

Magnetic Nanoparticles Based On Iron: Synthesis, Characterization, Design, And Application, Michael David Shultz

Theses and Dissertations

Magnetic nanoparticles are of great interest for a wide range of applications. This work has focused on three primary forms of iron based nanoparticles and combinations thereof: α-iron, iron oxide, and iron carbide or cementite. The synthesis of several core-shell particles including cementite-iron oxide, α-iron-cementite, and α-iron-iron oxide was accomplished through reverse micelle routes and high temperature decomposition of iron pentacarbonyl in various media. Structural analysis to confirm the structures was performed using extended x-ray absorption fine structure (EXAFS) techniques. A rapid characterization technique was developed utilizing a correlation between Fourier transform infrared spectroscopy and EXAFS to determine the full …

Effects, Uptake, And Fate Of 2,4,6-Trinitrotoluene Aged In Soil In Plants And Worms, Elly Ph Best, Henry E. Tatem, Kaaren N. Geter, Melissa L. Wells, Brian K. Lane

United States Army Corps of Engineers, Omaha District

The present study was aimed at providing data to be used at predicting exposure-based effects of 2,4,6-trinitrotoluene (TNT) aged in soil on endpoint organisms representing two trophic levels. These data can be used to define criteria or reference values for environmental management and conducting specific risk assessment. Long-term exposure tests were conducted to evaluate sublethal toxicity and uptake of aged soil-based explosives, with TNT as the main contaminant. In these tests, plants were exposed for 55 d, and biomass and explosives residues were determined. Worms were exposed for 28 and 42 d, and biomass, number, and tissue residues were determined. …

Nitrated Alpha-Synuclein-Activated Microglial Profiling For Parkinson’S Disease, Ashley D. Reynolds, Jason G. Glanzer, Irena Kadiu, Mary Ricardo-Dukelow, Anathbandhu Chaudhuri, Pawel Ciborowski, Ronald Cerny, Benjamin Gelman, Mark P. Thomas, R. Lee Mosley, Howard E. Gendelman

Ronald Cerny Publications

(PD). This can occur, in part, by modulation of glial function following activation by soluble or insoluble modified alphasynuclein (α-syn), a chief component of Lewy bodies that is released from affected dopaminergic neurons. α-Syn is nitrated during oxidative stress responses and in its aggregated form, induces inflammatory microglial functions. Elucidation of these microglial function changes in PD could lead to new insights into disease mechanisms. To this end, PD-associated inflammation was modeled by stimulation of microglia with aggregated and nitrated α-syn. These activated microglia were ameboid in morphology and elicited dopaminergic neurotoxicity. A profile of nitrated, aggregated α-syn-stimulated microglia was …

Phosphorylation Of Muc1 By Met Modulates Interaction With P53 And Mmp1 Expression, Pankaj K. Singh, Michelle E. Behrens, John P. Eggers, Ronald Cerny, Jennifer M. Bailey, Kandavel Shanmugam, Sandra J. Gendler, Eric P. Bennett, Michael A. Hollingsworth

Ronald Cerny Publications

MUC1, a transmembrane mucin, is a key modulator of several signaling pathways that affect oncogenesis, motility, and cell morphology. The interaction of MUC1 cytoplasmic tail (MUC1CT) with signal transducers and its nuclear translocation and subsequent biological responses are believed to be regulated by phosphorylation status, but the precise mechanisms by which this occurs remain poorly defined. We detected a novel association between the Met receptor tyrosine kinase and the MUC1CT. Met catalyzed phosphorylation of tyrosine at YHPM in the MUC1CT. Stimulation of S2-013.MUC1F pancreatic cancer cells with hepatocyte growth factor facilitated nuclear localization of MUC1CT, as determined by real time …

Influence Of Heterocyclic And Oxime-Containing Farnesol Analogs On Quorum Sensing And Pathogenicity In Candida Albicans, Roman Shchepin, Dhammika H.M.L.P. Navarathna, Raluca Dumitru, Shane Lippold, Kenneth W. Nickerson, Patrick Dussault

Patrick Dussault Publications

A series of synthetic molecules combining a geranyl backbone with a heterocyclic or oxime head group are quorum-sensing molecules that block the yeast to mycelium transition in the dimorphic fungus Candida albicans. A number of the analogs have an IC₅₀ ≤ 10 μM, a level of potency essentially identical to the natural quorum sensing signal, the sesquiterpene farnesol. Two of the most potent analogs, neither toxic toward healthy mice, display remarkably different effects when co-administered with C. albicans. While neither offers protection from candidiasis, one analog mimics farnesol in acting as a virulence factor, whereas the other …

Fumonisin Level In Corn-Based Food And Feed From Linxian County, A High-Risk Area For Esophageal Cancer In China, Jiansheng Wang, Ying Zhou, Wanbo Liu, Xiangcheng Zhu, Liangcheng Du, Qiaomei Wang

Liangcheng Du Publications

The level of mycotoxin fumonisins in corn-based food and feed collected from Linxian County, a high-risk area for esophageal cancer in China, has been analyzed using high-performance liquid chromatographic coupled with evaporative laser scattering detector (HPLC-ELSD). A total of 104 corn kernel samples were obtained from local households, granaries, wholesale markets (central markets), and retail markets (stores and supermarkets). Fumonisin B1 (FB1) was detected in the samples from households, granaries, central markets, and stores, with a positive rate of 61.5%, 50%, 33.3%, and 17%, respectively. No fumonisin was detected in samples from the supermarket. The highest FB1 levels (0.30–3.20 μg/ …

Mechanisms Of Hemoglobin Adaptation To High Altitude Hypoxia, Jay F. Storz, Hideaki Moriyama

Hideaki Moriyama Publications

Evidence from a number of vertebrate taxa suggests that modifications of hemoglobin (Hb) function may often play a key role in mediating an adaptive response to high altitude hypoxia. The respiratory functions of Hb are a product of the protein’s intrinsic O₂-binding affinity and its interactions with allosteric effectors such as protons, chloride ions, CO₂, and organic phosphates. Here we review several case studies involving high altitude vertebrates where it has been possible to identify specific mechanisms of Hb adaptation to hypoxia. In addition to comparative studies of Hbs from diverse animal species, functional studies of …

Mechanisms Of Hemoglobin Adaptation To High Altitude Hypoxia, Jay F. Storz, Hideaki Moriyama

Hideaki Moriyama Publications

Evidence from a number of vertebrate taxa suggests that modifications of hemoglobin (Hb) function may often play a key role in mediating an adaptive response to high altitude hypoxia. The respiratory functions of Hb are a product of the protein’s intrinsic O₂-binding affinity and its interactions with allosteric effectors such as protons, chloride ions, CO₂, and organic phosphates. Here we review several case studies involving high altitude vertebrates where it has been possible to identify specific mechanisms of Hb adaptation to hypoxia. In addition to comparative studies of Hbs from diverse animal species, functional studies of …

An Embarrassment Of Riches: The Enzymology Of Rna Modification, Dirk Iwata-Reuyl

Chemistry Faculty Publications and Presentations

The maturation of transfer RNA (tRNA) involves extensive chemical modification of the constituent nucleosides and results in the introduction of significant chemical diversity to tRNA. Many of the pathways to these modified nucleosides are characterized by chemically complex transformations, some of which are unprecedented in other areas of biology. To illustrate the scope of the field, recent progress in understanding the enzymology leading to the formation of two distinct classes of modified nucleosides, the thiouridines and queuosine, a 7-deazaguanosine, is reviewed. In particular, recent data validating the involvement of several proposed intermediates in the formation of thiouridines are discussed, including …

Unsymmetric Aryl–Alkyl Disulfide Growth Inhibitors Of Methicillin-Resistant Staphylococcus Aureus And Bacillus Anthracis, Edward Turos, Kevin D. Revell, Praveen Ramaraju, Danielle A. Gergeres, Kerriann Greenhalgh, Ashley Young, Nalini Sathyanarayan, Sonja Dickey, Daniel Lim, Mamoun M. Alhamadsheh, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

This study describes the antibacterial properties of synthetically-produced mixed aryl alkyl disulfide compounds as a means to control the growth of Staphylococcus aureus and Bacillus anthracis. Some of these compounds exerted strong in vitro bioactivity. Our results indicate that among the twelve different aryl substituents examined, nitrophenyl derivatives provide the strongest antibiotic activities. This may be the result of electronic activation of the arylthio moiety as a leaving group for nucleophilic attack on the disulfide bond. Small alkyl residues on the other sulfur provide the best activity as well, which for different bacteria appears to be somewhat dependent on …

Inhibition Of Cellular Thioredoxin Reductase By The Anticancer Prodrug Cloretazine, Tyler R. Schleicher

Honors Theses

Sulfonylhydrazines are a class of DNA alkylating drugs which also produce carbamoylating activity in situ. The carbamoylating species is of significance because it has shown to inhibit important thiol-containing enzymes such as glutathione reductase (GR) and thioredoxin reductase (TrxR). TrxR catalyzes dithiol-disulfide exchange reactions on thioredoxin (Trx), which in turn catalyzes other reductive processes such as deoxyribonucleotide biosynthesis. In this study, we demonstrate that TrxR activity is strongly inhibited by the anticancer prodrug Cloretazine both in purified form and in leukemia cell lysates. This inhibition is specific to the carbamoylating activity of methylisocyanate (MiC). In contrast, another important oxidoreductase, glutathione …

The Development Of A "Genetic Eyewitness" Profiling System For Low Template Forensic Specimens: Identification Of Novel Protein, Rna, And Dna Biomarkers, Erin Hanson

Electronic Theses and Dissertations

In many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be available. An increasing reliance therefore is placed on the biological evidence recovered during criminal investigations to act as a silent witness, providing unbiased and scientific information that may aid in the resolution of …

Mechanistic Investigations Of The Trans Excision-Splicing And Trans Insertion-Splicing Reaction, Perry Patrick Dotson Ii

University of Kentucky Doctoral Dissertations

Group I intron-derived ribozymes are catalytic RNAs that have been engineered to catalyze a variety of different reactions, in addition to the native self-splicing reaction. One such ribozyme, derived from a group I intron of Pneumocystis carinii, can modify RNA transcripts through either the excision or insertion of RNA sequences. These reactions are mediated through the trans excision-splicing (TES) or trans insertionsplicing (TIS) reaction pathways. To increase our current understanding of these reactions, as well as their general applicability, a mechanistic and kinetic framework for the TES reaction was established. Furthermore, additional ribozymes were investigated for their ability to …

Electrical Detection Of The Temperature Induced Melting Transition Of A Dna Hairpin Covalently Attached To Gold Interdigitated Microelectrodes, Greg P. Brewood, Yaswanth Rangineni, Daniel J. Fish, Ashwini Bhandiwad, David R. Evans, Raj Solanki, Albert S. Benight

Chemistry Faculty Publications and Presentations

The temperature induced melting transition of a self-complementary DNA strand covalently attached at the 5' end to the surface of a gold interdigitated microelectrode (GIME) was monitored in a novel, label-free, manner. The structural state of the hairpin was assessed by measuring four different electronic properties of the GIME (capacitance, impedance, dissipation factor and phase angle) as a function of temperature from 25 degrees C to 80 degrees C. Consistent changes in all four electronic properties of the GIME were observed over this temperature range, and attributed to the transition of the attached single-stranded DNA (ssDNA) from an intramolecular, folded …

The Cis-Δ2,3-Double Bond Of Phoslactomycins Is Generated By A Post-Pks Tailoring Enzyme, Nadaraj Palaniappan, Mamoun M. Alhamadsheh, Kevin A. Reynolds

Chemistry Faculty Publications and Presentations

The antifungal phoslactomycins (PLM A-F), produced by Streptomyes sp HK803, are structurally unusual in that three of their four double bonds are in the cis form (Δ^12,13, Δ^14,15, Δ^2,3). The PLM polyketide synthase (PKS) has the predicted dehydratase catalytic domain in modules 1,2 and 5 required for establishing two of these cis double bonds (Δ^12,13Δ^14,15), as well as the only trans Δ^6,7double bond. By contrast, the formation of the cis Δ^2,3 in the unsaturated lactone moiety of PLMs has presented an enigma because the predicted dehydratase domain …

Development And Forensic Application Of Dye Probe Fluorescence Resonance Energy Transfer For Improved Detection Of Changes In Dn, Micah Halpern

Electronic Theses and Dissertations

Discovering, screening, and associating changes in DNA sequence are important to a broad range of disciplines and play a central role in Forensic Science. The typical types of changes include sequence variations [single nucleotide polymorphisms (SNP)] and length variations [short tandem repeats (STR)]. The steps for forensic DNA sample processing are similar for both types of changes but diverge at the point of detection. A number of approaches are being explored for SNP genotyping while STR analysis primarily consists of size-based analysis by capillary electrophoresis. Limitations exist for all current detection methods that pose significant impacts to forensic analysis. Bi-allelic …

The Identification Of Ignitable Liquids In The Presence Of Pyrolysis Products: Generation Of A Pyrolysis Product Database, Joseph Castelbuono

Electronic Theses and Dissertations

The fire debris analyst is often faced with the complex problem of identifying ignitable liquid residues in the presence of products produced from pyrolysis and incomplete combustion of common building and furnishing materials. The purpose of this research is to investigate a modified destructive distillation methodology provided by the Florida Bureau of Forensic Fire and Explosive Analysis to produce interfering product chromatographic patterns similar to those observed in fire debris case work. The volatile products generated during heating of substrate materials are extracted from the fire debris by passive headspace adsorption and subsequently analyzed by GC-MS. Low density polyethylene (LDPE) …