Chemistry Commons^™

Nickel Subsulfide Can Protect Human Fibroblasts From The Mutagenic Effect Of Benzo[A]Pyrene Diolepoxide, Samir M. Hamdan

Masters Theses

Cancer researchers are interested in identifying the environmental causes and synergistic influences of different carcinogens. It is important to examine the combined effect of multiple carcinogens since this is a more realistic representation of the true environmental situation in which we are exposed daily. Our study has reported that pretreating human fibroblasts with nickel subsulfide followed by the simultaneous treatment with both nickel subsulfide and benzo[a]pyrene diolepoxide (BPDE) can protect human fibroblasts from the mutagenic effects of BPDE. These results correlate well with our previous chromium-BPDE co-treatment work, suggesting a transition metal dependent protective effect. This protective effect was dependent …

Separation And Determination Of Monochlorophenols By Capillary Zones Electrophoresis, Zarina Yasmin Banu

Masters Theses

Chlorine has been widely used in industry. One of the most common uses of chlorine is in municipal water treatment plants. Chlorine reacts with a variety of organic compounds, among these are phenol and its derivatives which are commonly found in natural waters. When these compounds react with chlorine, a variety of chlorine substituted and oxidized products result depending on concentrations, pH, and temperature. In order to study these reactions it is necessary to separate and determine the various products produced.

Earlier studies have shown 3-chloro and 4-chlorophenol cannot be separated by commercial GLC columns. GC/MS (electron impact) measurements cannot …

Improvement Of Epa Method 8330: Complete Separation Of Explosives Using A Two Phase Approach, Michael J. Lang

Masters Theses

A wide range of primary and secondary contaminants is found in environmental matrices containing explosive residues. HPLC methodology for the detection of explosive is now standardized in EPA Method 8330, and represents the most common method currently used for explosive analysis. However, co-elution of some of the analytes occurs even using method 8330. As a result, explosive analysis using HPLC have required the use of a confirmation column in an additional analysis step.

In the current work, all of the compounds in the EPA 8330 explosives list were resolved using a single HPLC separation. While the EPA 8330 HPLC conditions …

A Method For The Determination Of Purity Of Pnu-10483 Bulk Drug By Capillary Zone Electrophoresis, Gavin Gibson

Honors Theses

In this investigation, a method was developed for the determination of purity of the drug PNU-10483 using the technique of capillary zone electrophoresis (CZE). CZE was seen as a potential alternative to the formerly used procedure of ion-pair reversed phase highperformance liquid chromatography (HPLC). Nearly five years earlier, a similar study was performed, in which an attempt was made to develop a method that used CZE to determine the purity of bulk drug and the potency of drug tablets. While this development was mostly successful, sporadically unpredictable results reduced the method's overall viability. These outliers were thought to be caused …

Pan, Ppn And Mpan Measurements And The Systematic Relationship Between Mpan And Macr At A Semi-Rural Site In Tennessee, George Nouaime

Masters Theses

Simultaneous measurements of peroxymethacryloyl nitrate (MPAN) and its primary and secondary precursors, methacarolein (MACR) and isoprene, were carried out for the first time in July 1995 at a semi-rural site southeast of Nashville. In addition to these compounds, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), other volatile organic compounds (VOCs) and supporting measurements were also collected in collaboration with other research groups. The mean concentrations of PAN, PPN, MPAN and MACR were found to be 485 pptv, 50 pptv, 30 pptv and 0.290 ppbv respectively. MP AN levels, which closely tracked those of MACR during the day, peaked and dropped earlier …

Elucidation Of The Pathway Required For The Stimulation Of G6pdh Gene Expression By Insulin And Its Mimetics, Asavari Wagle

Masters Theses

Insulin, an anabolic hormone, exquisitely controls cellular physiology and metabolism by modulating the activity of key proteins which regulate metabolic and mitogenic events. Insulin activates several cytosolic proteins via a phosphorylation cascade, but only some of these proteins are required for its specific action. We have elucidated the insulin signal transduction cascade in primary rat hepatocytes, and outlined some of the events that are required for the insulin induced stimulation of glucose-6-phosphate dehydrogenase (G6PDH) gene expression. Using well-characterized and structurally different inhibitors, we show that insulin stimulation of the gene requires the IRS-1/P13K pathway and not the RAS/RAF/MAPK pathway. Gene …

Extraction Of Premafloxacin Radiolabeled With Carbon Fourteen From Loam Soil, Steven Gregory Staskiewicz

Masters Theses

Premafloxacin is a fluoroquinolone antibiotic being developed by Pharmacia & Upjohn for veterinary indications. Since the parent drug and possibly metabolites will be applied to soil through the deposition of animal excreta, many regulatory agencies will require environmental assessment testing. In order to determine if ¹⁴C-premafloxacin would biodegrade in the soil, loam soil was extracted with solvents and C18 solid phase columns were used to isolate the compound after three weeks of incubation. In addition to extracting the soil, production of ¹⁴CO₂ was monitored by trapping the degradation by-product in 2 N NaOH. Liquid scintillation counting of …

Synthesis Of Biologically Active Substituted Chalcones, Kiel Steven Hoff

Masters Theses

Two different synthetic routes to poly-hydroxylated chalcones are investigated. The wittig synthesis and protection of the hydroxyl functionalities by forming the methyl ether followed by the base catalyzed Claissen-schmidt reaction and then deprotection were investigated. It was demonstrated that the protection-condensation- deprotection route was more efficient. The antiviral activity of 2,2', 4' - trihydroxychalcone against the HIV virus is also presented.

Analysis Of Organic Nitrates In Artic Outflow, Deanna Elyea-Piper

Masters Theses

The Arctic Outflow Study (AOS) was a project funded by the National Science Foundation to assess the impact of tropospheric ozone concentrations by the measurement of oxidized nitrogen. Measurements of arctic outflow were made to assess the seasonal cycle of compounds in arctic air and the partitioning of NOy during transport to the North Atlantic region. These photochemically active compounds are elevated in the arctic during the winter and spring because of the lack of photochemical processes to destroy them.

Measurements of PAN, Alkyl nitrates, NOy, NO, NO₂, CO, HNO₃, O₃, and particulate nitrate …

Thermal Studies Of Complex Formations Of First Row Transition Metals With Phenolic Compounds In Aqueous Solution, Nabil Adnan Amro

Masters Theses

The coordination chemistry of protocatechuic acid and catechols with the first row of transition metals was studied as a model for the more complicated natural humic substance.

The reaction between Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and the phenols, catechol and protocatechuic acid in aqueous solution was studied by the spectrophotometric method. The composition of the complexes formed was determined by continuous variation, iso-molar series and molar ratio methods. The presence of complexes with metal:ligand ratio of 1:1, 1:2 and 1:3 was established in the pH range 3 to …

Nickel Catalyzed Cyclizations Of Alkynyl-Etones And Their Application To The Formal Synthesis Of Pentalenic Acid, Kevin Schlosser

Honors Theses

Pentalenic acid is a very important molecule because it is a biosynthetic intermediate of pentalenolactone, which has antibiotic effects on Grampositive/ negative bacteria and pathogenic fungi. These effects are due to its ability to inhibit glyceraldehyde 3-phosphate dehydrogenase.1 However, the total synthesis of pentalenic acid is very lengthy.2 This project will begin the process of finding a more convenient route to pentalenic acid. Previously in this laboratory there have been experiments conducted in the cyclization of enones with nickel (0)3 It is hypothesized that this method can be used to shorten the preparation of pentalenic acid. As illustrated by the …

Side Chain Effect On Micellarly Catalyzed Hydrolysis Of Hydroxamic Acids In Perfluorooctanoic Acid Environment, A.C. Menik Fernando

Masters Theses

The side chain effect on micellar catalysis of hydroxamic acids with perfluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution has been demonstrated in this thesis.

The rate constant-surfactant concentration profiles were used to estimate the critical micelle concentration and the second order rate constant for hydrolysis in the aqueous bulk phase.

The pseudo-phase ion exchange model satisfactorily explains the surfactant effect. The second order rate constants in the aqueous bulk phase show a direct relationship with steric substituent constants. The major influence of the change in micellar catalysis is the location in the micelle where the substrate …

The Effect Of Chromium Compounds On The Mutagenic Rate Of Benzo[A]Pyrenediolepoxide In Human Fibroblasts, Yordanos Tesfai

Masters Theses

Cancer researchers are interested in identifying the environmental causes and synergistic influences of different chemical carcinogens in order to decrease the risk of cancer. There are numerous studies which have investigated the effect of individual carcinogens but relatively few in which a well defined mixture of chemicals have been used. The present study was performed to examine the effect of chromium compounds on benzo[a]pyrene diolepoxide (BPDE) induced cytotoxicity and mutagenicity in human fibroblasts. Cytotoxicity was measured by the ability to fonn colonies while selection of 6-thioguanine resistant mutants were used to study mutagenesis in human fibroblasts.

Our results indicate that …

Rapid Method For Determination Of Iodine Numbers Of Vegetable Oils, Ondrej Hendl

Masters Theses

There is a great deal of interest by the public about the total unsaturation of fats and oils used in commercial products as an indication of nutritional value. Dealers in fats and oils are extremely interested in characterizing these products. The unsaturation is a guide to the expected stability of food additives, such as edible oils and foods in which they are used. Unsaturation is typically evaluated as an iodine number (IN), calculated for these additives based on their consumption of iodine through addition across the carbon-carbon double bonds. The classical titration method can typically take 45 minutes.

The investigation …

A Hplc Method To Assay Mycotoxins - Fumonisin, Ochratoxin And Zearalenone, Nalini Sadagopan

Masters Theses

A HPLC method to quantitate the mycotoxins Fumonisin B1 (FB1), Ochratoxin A(OA), and Zearalenone (ZON) was developed and validated. Mycotoxins are secondary metabolites of fungi like Fusarium, Asperigillus and Penicillium that contaminate crops. They have a wide array of chemical structures which facilitate their analytical detection.

The analytical method consists of reverse phase chromatography and fluorescence detection. Sample cleanup was performed using SAX and C18 cartridges prior to analysis on the HPLC.

The method developed for FB1 is unique in that it is more sensitive, accurate, and reproducible than the existing methods. Automation is one of the salient features that …

Reactions Of Chlorine And Some Of Its Oxygen Derivatives With Phenol, Lizhuo Zhang

Masters Theses

Chlorine is widely used in industry. It is also the most commonly used disinfectant in water treatment plants. Since the amount of chlorine used is increasing each year, environmental and health concerns arise due to its reactivity with various of organic compounds. Many chlorinated organic compounds are toxic and as a result other non-chlorinating compounds, such as chlorine dioxide, might be potential substitutes in the future, especially in water treatment plants.

Previous studies have indicated that chlorinated organic compounds are not formed when chlorine dioxide is used as a disinfectant. Furthermore no reaction occurs between chlorite and phenol in the …

An Investigation On Nonenzymatic Autoxidation Of Phenolic Compounds In Natural Waters, Lei Jiang

Masters Theses

The nonenzymatic autoxidation of the phenolic compounds chlorogenic acid in aqueous solution was studied. The study demonstrated that the oxidation rate of chlorogenic acid was strongly dependent on pH. The higher the pH, the faster the rate of oxidation. The involvement of phenolate ions and radicals in oxidation reactions are two possible reasons for the pH dependency. The presence of a trace amounts of reducible transition metal ions, such as copper(II), dramatically increases the oxidation rate of chlorogenic acid. Light also increases the oxidation rate of chlorogenic acid. However, the photochemical reaction was a much slower process.

The TLC and …

A Graph Theoretic Study Of The Similarity Of Discrete Structures, Heather D. Gavlas

Dissertations

A basic problem in drug design consists of finding a compound that satisfies a spectrum of biological and chemical properties. Although drug design problems are central to pharmaceutical research, statisticians have yet to become involved in this area as these problems are viewed statistically as optimization problems. Before statistical optimization procedures can be defined on these spaces whose points are structures and not vectors, very basic mathematical notions of distance must be defined. Graphs have been used as mathematical models to represent the bonding arrangements of molecules for quite some time. In fact, if some of the methodology used by …

Effects Of Insulin And Insulin Mimetics On Antioxidant Enzyme Levels: In Vivo And In Vitro, Shikha Varma

Masters Theses

Tissue antioxidation status is considered to be an important factor for elucidating the etiology of diabetes and its physiological complications. This study was aimed to determine the in vivo antioxidant enzyme levels in the altered antioxidant status of diabetic rat liver with the treatment of two potent insulin mimetics, vanadium and selenate. The direct effects of vanadate, selenate, and zinc (another insulin mimetic) on the antioxidant enzyme levels in primary rat hepatocytes in culture was also determined. Levels of superoxide dismutase (SOD), catalase (CAT) and gluthahione peroxidase (GPX) were determined in both model systems.

In the vivo model, insulin treatment …

Regulation Of The Expression Of Lipogenic Enzymes By Insulin-Mimetics, Juiyu Wu

Masters Theses

Many researchers have shown that selenate (SeO₄^2-) and vanadate (VO₄^2-) have insulin-mimetic effects in certain biological processes. These mimetic effects include increasing glucose transport, regulating glycolytic enzymes, normalizing plasma glucose levels and activities of insulin regulated enzymes in diabetic rats. To clarify the functions and roles of these insulin-mimetics in different insulin-regulated metabolic pathways, the expression of the genes for glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) were investigated. G6PDH is a key enzyme in the pentose phosphate pathway and is also involved in lipogenic metabolism by providing 55-70% of the NADPH utilization …

The Separation Of Aqueous Iron Species Found In Stepwise Complexation By Capillary Electrophoresis With Atomic Absorption Spectroscopy Detection, Robert E. Sutton

Dissertations

A capillary zone electrophoresis system was interfaced to an atomic absorption spectrom eter to permit the separation and detection o f various species of iron found in step wise complexation in aqueous solutions. The samples were introduced at the anodic end of the column employing the electroosmotic flow to drive all the species to the detector at the cathodic end. Aqueous solutions of iron(II) and iron (III) chloride salts were among the compounds studied. The buffer employed w as a 20 millimolar (2-[N-morpholino]ethanesulfonic acid adjusted to a pH of 6 with 6 .6 millimolar potassium hydroxide. The detection limit was …

Structural Effects On Micellar Catalyzed Hydrolysis Of Hydroxamic Acids With Perfluorooctanoic Acid As Surfactant, Xing Zhang

Masters Theses

This thesis demonstrated the structural effects on micellar catalyzed hydrolysis of hydroxamic acids with prefluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution.

For different hydroxamic acids, the observed pseudo-first order rate constant-surfactant concentration profiles were obtained and were used in the determination of critical micellar concentrations (cmc).

The micellar catalytic effect was satisfactorily explained by the pseudo-phase ion exchange (PPIE) model. The PPIE model was successfully applied in the determination of the reaction rate constants both in the water phase and in micellar pseudo-phase.

Further investigation into more appropriate hydroxamic acids is suggested in order to obtain …

The Reaction Of Caffeic Acid And Copper (Ii) In Natural Water, Ling Xiaozheng Xu

Masters Theses

The interaction of the lignin precursor compound caffeic acid with copper(lI) in aqueous solution was studied. In the presence of a reducible transition metal, such as copper, caffeic acid undergoes oxidation. Oxygen was shown to play an important role in the reaction. The UV-visible data demonstrated that the conjugated double bond in the propenoic acid side chain of caffeic acid slowly disappeared during the reaction. The molecular weight experiments indicated that the product was a dimer. FTIR spectrum agreed with two possible dimer structures involving the side chain of caffeic acid. In addition, the reaction was shown to be reversible. …

Photoionization With Excitation Of The 4s And 4p Subshells In Krypton, Ahmad Farhat

Masters Theses

High-resolution photoelectron spectra of the nd, Rydberg satellites in krypton have been measured for the first time for six different angles and for photon energies between 68.5 and 250 eV. The relative intensities of these satellites with respect to the 4s and 4p main lines are in very good accord with the most recent measurements of Krause et al. (1992) at 68.5 eV. They also confirm that the theoretical predictions for the relative intensity of these satellites are too high. We determine the ratios for nd satellites with respect to the 4s and 4p main lines, and extract the angular …

Application Of A Modified Analytical Derivatization Method To The Determination Of Microbial Metabolites In Aquifer Systems, Jie Lu

Masters Theses

The geochemical evolution of Low Molecular Weight Fatty Acids (LMWFA's) in various ground water samples and aquifer solid samples from both contaminated and uncontaminated sites has been studied. An improved analytical method has been established for both qualitative and quantitative determination of LMWFA's. The low molecular weight (LMW) organic acids are metabolic intermediates of the oxidative biodegradation of hydrocarbon contaminants. The hydrocarbons are believed to be the electron donors in these redox reactions. Formic and acetic acids were found to be the major LMWFA's in these ground water samples and aquifer solid samples. Their concentrations increase as the redox condition …

Quantitative Analysis Of Steroids By 13C Nmr Spectroscopy, Pei Wang

Masters Theses

Steroids are usually analyzed quantitatively by using HPLC with ultraviolet detection and are confirmed by FTIR, GC-MS. Quantitative ¹³C NMR method provide an alternative means to analyze steroids. Chromatographic separation and subsequent identification by match with a spectroscopic data base spectrum is not required for quantitative analysis of mixture components. Instead, equivalent information is obtained by creating subspectra from resonances with equivalent peak areas within a quantitative NMR spectrum. Techniques for eliminating Nuclear Overhauser Enhancement (NOE) effect is described.

Approaches To And Synthesis Of Chalcone Amides, Gregory S. Marczak

Masters Theses

A series of "chalcone" amides have been prepared. These amides are unique in the position of the substituted hydroxy and methoxy functional groups. Early approaches to the synthesis of the amides proved difficult when preparing intermediates from the phenolic substituents. These phenols were then protected to lead to easier formation of the intermediates, and then deprotected to yield the corresponding chalcone amides. The approaches to the preparation of these compounds is presented, along with the physical data used to characterize the chalcone amides.

Identification Of Aromatic Acids As Microbial Metabolites Of Fossil-Fuel Compounds Present In Aquifer Systems, Daniel Michael Tomczak

Masters Theses

The identification and quantitation of aromatic acids as transformation products present in contaminated aquifer systems was studied from selected sites. These acids are formed as microbial metabolites in the oxidative degradation of aromatic compounds. The microbial activity in the subsurface can be coupled to the oxidation of the aromatic compounds and the reduction of specific inorganic indicators. Inorganic indicators identified from the sample sites include the reduced forms of iron, nitrate, sulfate, and dissolved oxygen.

The highest concentrations of the aromatic acids were found in the plumes of the contaminated sites. These concentrations also correlated with specific changes in concentrations …

Separation Of Copper And Iron In Natural Waters By Solid-Phase Extraction, Charles Bui

Masters Theses

A separation scheme has been developed by utilizing Solid-Phase Extraction cartridges in order to isolate and characterize the charge of metals and their complexes in natural waters. These species can be analyzed by Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma (ICP), and Ultraviolet-Visible Spectrophotometry (UVVIS).

This separation scheme would permit the determination of the concentration of metals, as well as providing information about the forms in which the metals exist, e.g., charge of metallic complexes.

Synthetic metal complexes were prepared in the laboratory in order to study the separation scheme as well as trying to understand the binding stability of …

Thermodynamic Properties Of Mixtures Of Aqueous Solutions Of Hydrochloric Acid And Cadmium Chloride, Copper Chloride, Manganese Chloride, And Zinc Chloride, Samia A. Kosa

Masters Theses

The densities of mixtures of aqueous solutions of hydrochloric acid and cadmium chloride, copper chloride, manganese chloride, and zinc chloride have been measured at constant ionic strengths of 1.0 and 3.0 molal at 25 °C. In the case of HCl, CdCl₂ , and ZnCl₂ the literature data were refit using Pitzer' s apparent molal volume equation and the binary solution parameters were determined. Density data were used to determine the volume of mixing (∆V_m). Data from Torok and Berecs were combined with our data for the mixtures with CuCl₂ and MnCl₂. Pitzer's volume …