Chemistry & Biochemistry
Permanent URI for this collectionhttps://hdl.handle.net/11274/15812
Browse
Browsing Chemistry & Biochemistry by Issue Date
Now showing 1 - 20 of 64
- Results Per Page
- Sort Options
Item Identifying chlorhexidine and sodium hypochlorite reaction products and the environmental implications of its interaction with cotton fibers(Dec-23) Huynh, Stacy 1997-; Beatty, John; Salazar, Gustavo; Lin, ShiruChlorhexidine is heavily used in the medical and dental field and is prescribed for multiple uses related to healthcare. When in contact with sodium hypochlorite, chlorhexidine breaks down into several toxic compounds that are not fully understood, and these compounds have impacts on the environment and human health, due to its heavy use in the medical field. Chlorhexidine breaks down into compounds that permanently adhere to and damage the cellulose fibers found in cotton fabrics and alter the visible quality of fabric, which leads to re-washing of fabrics or outright disposal of fabric due to the staining and damage. Chlorhexidine is also used in conjunction with sodium hypochlorite in dental procedures, such as root canals, and the toxic nature of this interaction is not fully understood. Previous studies have identified several products of this reaction, one being para-chloroaniline, suggesting that chlorhexidine should not be used in conjunction with chemical oxidizers like bleach until the toxic products are further studied and identified. Understanding how chlorhexidine interacts with textile fibers like cellulose will save water and cotton fabric from being prematurely disposed of and negatively impacting the environment. This project will work to understand the reaction between chlorhexidine and sodium hypochlorite, the toxic products that result from this reaction, and its interactions with cotton fiber textiles to reduce its impact on health and the environment.Item Syntheses and characterizations of homoleptic and heteroleptic copper complexes with monocyclic and polycyclic azine ligands(Dec-23) Kouadio, Halima; Omary, Manal; Mirsaleh-Kohan, Nasrin; Salazar, GustavoThis thesis is concerned with the following ligands to use to coordinate and react to copper: a pyrimidine: niacinamide, the polyazine monocyclic triazine: cyanuric acid, and bicyclic N- donating hydrocarbons: quinoxaline and caffeine. When reacted with cuprous salts consisting of organic ligands they form multi-ligand coordination supramolecular architectures (1) or halides to form copper halide clusters. In the novel compounds, metal-metal interactions occur, which exhibit low-lying triplet state charge transfers, allowing the tunability of a photon-emitting compound which is expected to form the emission. Cuprous metal centers also possess the ability to self-assemble to form coordination polymers. Group 11 d10 coinage metals exhibit strong metal-to-ligand charge transfers (MLCT) as well.(50) Characterization of all compounds was completed using thermogravimetric analysis, X-ray crystallography, Fourier transform infrared spectroscopy (FTIR), and photoluminescence spectroscopy. The acquired data is analyzed and discussed further in the following thesis.Item Synthesis and characterization of diverse copper halide complexes with a range of heterocyclic ligands(Dec-23) Diaby, Aminata 1988-; Dr. Manal Omary; Mirsaleh-Kohan, Nasrin; Dr. Richard SheardyThis study aimed to compare the stability, physical, and chemical attributes of Cu(I) and Cu(ACN) metals, investigating their resemblances and disparities. It comprises approximately 137 pages, encompassing 90 figures, 16 tables, and references. The research focused on synthesizing and characterizing Cu(I) complexes with azole family ligands. Two methodologies were applied: the first involving CuI and Cu(CH3CN) (where X = I or CH3CN) reacting with single ligands like 3,5-diisopropylpyrazole, 3,5-diphenolpyrazole, 3,5-(tert)-butylpyrazole, and 5-(4-chlorophenyl)-1H-tetrazole. The second utilized Cu(CH3CN) with mixed ligands specifically 3,5-diphenolpyrazole and pyrazine, as well as 3,5-(tert)-butylpyrazole and pyrazine. Complex synthesis occurred via solvent-mediated routes using the Schlenk technique and solvent-free reactions with mechanical grinding. Comprehensive characterization involved techniques such as melting point determination, solubility tests, luminescence spectroscopy, FT-IR, TGA, elemental analysis, NMR, and X-ray crystallography. Ligands were characterized using the same listed techniques to understand changes. All synthesized products underwent thorough characterization using diverse analytical tools.Item HPLC analysis to assess efficacy of cisplatin, nedaplatin, and oxaliplatin(Dec-23) Hernandez, Jessica 1990-; Mirsaleh-Kohan, Nasrin; Beatty, John; Salazar, GustavoPlatinum drugs are one of the most widely used agents against cancerous cells. Cisplatin’s chemotherapeutic efficacy is limited by the increase of tumor resistivity and unwanted side effects. Cisplatin’s cytotoxicity is linked to its ability of forming 1,2-intrastrand adducts with adjacent guanine (G) bases. An analytical method to detect and quantify the amount of platinum bound to DNA is necessary to enhance and develop anticancer drugs. In this work, High Performance Liquid Chromatography (HPLC) analysis was performed to assess the binding of cisplatin, nedaplatin, and oxaliplatin to the dinucleotide dGpdG. By examining the concentration ratios and incubation periods at 37 °C, we measured the amount of platinum drug reacted with DNA (platination rates) indicating the percentage of Platinum-DNA (Pt-DNA) adducts. Cisplatin proved to be the most effective, followed by nedaplatin, and then oxaliplatin. This research has implications in designing more efficient anticancer drugs.Item Synthesis of doxorubicin-protein conjugates via cobalt coordination chemistry(May-23) Colion, Sara; Petros, Robby; Beatty, John; Mirsaleh-Kohan, NasrinThe use of nanotechnology-based drug delivery systems in the context of cancer treatments has the potential to help target drug chemotherapeutics to tumor cells more precisely while simultaneously reducing off-target toxicity. One of the most prescribed chemotherapeutics, doxorubicin, is an anthracyclines drug that is effective in treating cancer; however, the drug exhibits dose-limiting cardiotoxicity. Dox intercalates DNA, resulting in the deterioration of DNA strands and the ultimate inhibition of DNA and RNA synthesis. Doxorubicin’s chemical structure contains a primary amine group that can be used to crosslink it to a protein. This project focuses on using cobalt coordination chemistry as a novel crosslinking strategy to synthesize conjugates of Dox bound human serum albumin (HSA). The synthesis of conjugates of Dox with HSA will be discussed along with methods for characterization via HPLC that allow the number of Dox molecules bound per protein molecule to be determined.Item Thermomyces Lanuginosus Xylanase Unfolds to a Structure with Large Random Coi Content Below 24 $#730;C AT pH 7.0(1/1/2013) Arrington, Tara M.; Britt, Billy M.; Sheardy, Richard Dean; Rawashdeh-Omary, ManalThermomyces lanuginosus xylanase is a thermophilic enzyme with maximum activity at 55 °C. Previous work in our laboratory has determined that it undergoes a large conformational change at 24°C involving a volume change of approximately 190 L/mol upon going from the physiological-temperature conformer to the low-temperature conformer. This value was determined through previous research from our laboratory using the Clapeyron equation. Our current investigation is to determine whether this protein is fully unfolded or exists as a molten globule below the transition temperature. Our methods for detection are dynamic light scattering, differential scanning calorimetry and circular dichroism. We found that the structure is best characterized as random coil rather than molten globule below 24 °C.Item Understanding the conformations and stabilities of g-quadruplexes formed by human telomere sequence in ideal and less ideal solutions(1/1/2014) Sharma, Vishal Rajat; Sheardy, Richard Dean; Mirsaleh-Kohan, Nasrin; Rawashdeh-Omary, ManalThe G-rich termini of human chromosomes, called telomeres, have the ability to form unique DNA structures called G-Quadruplexes, which have been implicated in certain cancer types and, as a result, have drawn researchers' attention to study their structure inside the cell and thus consider them as potential targets for new anticancer therapies. Biophysical studies of these entities have been carried out under near ideal conditions, i.e., low phosphate concentration (e.g., 10mM), pH 7, low ionic strength (e.g., 115mM), and for optical studies, low concentration of DNA (e.g., 1 × 10-6 M). We, here, created less ideal conditions by using different osmolytes such as polyethylene glycol, acetonitrile, trifluoroethanol, and betaine. Our research focuses on the effect of these co-solutes on the structural and thermodynamic properties of telomeric DNA oligomers and report the characterization of (TTAGGG)x, where x = 1, 2, or 4. In general, increasing the percentage of any osmolytes in solutions drives the equilibrium from unimolecular hybrid to multimolecular parallel conformation. In addition, Stability of parallel conformation also increases.Item Design and photophysical characterizations of new copper(I) and silver(I) mixed ligand complexes with “green chemistry” incorporation(1/25/2022) Jawaid, Ramsha; Rawashdeh-Omary, ManalThis thesis is a study of mixed ligand coinage metal complexes. It has 122 pages, 68 figures, 14 tables, and the references. It discusses one main project divided by three chapters describing in general the synthesis, structure and spectroscopic studies of silver (I) and copper (I) complexes. Chapter I discusses the introduction to trinculear pyrazolate complexes of d10 coinage metals, N-donor heterocyclic ligands, polycyclic aromatic hydrocarbon ligand, mixed-metal and mixed-ligand complexes. It also investigates the impact of structural factors and various synthetic conditions on photophysical properties as well as the potential applications including sensors for (VOCs), metal-organic frameworks (MOFs), solar cells and organic light emitting diodes (OLEDs). Chapter II involves both solvent-mediated and solvent-less synthetic routes of silver (I) and copper (I) complexes and mixed-metal and mixed-ligand complexes and their characterization through elemental analysis, x-ray crystallography, melting point, photoluminescence, 1H NMR, FT-IR, absorption spectroscopy and thermogravimetric analysis. Chapter III summarizes the conclusion of the results obtained in chapter II and the expected applications of similar compounds in the industry.Item Copper phenanthroline complexes in a new era: Utilizing “green” chemistry in the synthesis of cu-phen coordination complexes(1/30/2019) Wilk, Mikaela; Sheardy, Richard DeanThe purpose of this research was to expand on the knowledge of a well know organometallic system: copper phenanthroline complexes. Copper phenanthroline complexes have been widely studied and are currently being investigated for uses in catalysis, medicine, and solar energy applications. It was the goal of this research to synthesize well known useful complexes using new solventless synthesis methodology as well as to create new materials to study for potential application in these fields. This thesis includes 134 figures, 64 tables, and is 189 pages long. Eight compound have been synthesized and characterized through techniques such as X-ray crystallography, elemental analysis, thermogravimetric analysis, melting point, 1H-NMR, Fourier transform infrared spectroscopy (FTIR), electronic absorption spectroscopy, diffuse reflectance spectroscopy, and photoluminescence spectroscopy. Analysis of the results are discussed and conclusions about potential applications are made.Item Fine and coarse tuning of the photophysical and chemical properties of cuprous iodide complexes with various imine based ligands(1/9/2018) Scoggins, Laura E; Sheardy, Richard Dean; Mirsaleh-Kohan, Nasrin; Rawashdeh-Omary, ManalThis thesis is a study of copper iodide complexes with various imine based ligands. It has 150pp, 17 tables, 112 figures and the references for the study of these CuI complexes. The one main project is discussed over four chapters unfolding the synthesis, structure and spectroscopic studies of the copper iodide complexes. Chapter I introduces the background of copper halide complexes, physical and photophysical properties of these complexes, and their potential applications. Chapter II discusses the synthesis of each copper iodide complex. Chapter III covers the characterization of the synthesized compounds including x-ray crystallography, elemental analysis, photoluminescence, lifetime, 1HMNR, FT-IR, absorption spectroscopy and thermogravimetric analysis. Chapter IV concludes and summarizes the results obtained in chapters II and III and the expected applicationsItem Damage mechanisms of anticancer agents: Platinum-based drugs and copper complexes(10/3/2018) Nguyen, Trang Thi Minh; Mirsaleh-Kohan, Nasrin; Rawashdeh-Omary, ManalCisplatin and carboplatin, which belong to the platinum based-drugs family are accustomed to treat various types of cancers. Although they have been used widely in chemotherapy, cisplatin and carboplatin are confronting some issues such as toxicities and drugs resistances. Therefore, designing a new drug without those issues is a challenge. In this study, the technique of Surface-Enhanced Raman Scattering (SERS) is employed in order to research the modification to guanine when cisplatin or carboplatin bound. The success in clinical use of cisplatin has put metal-based drugs on the first row for cancer treatment. Other than platinum complexes, copper complexes gain major attraction to many scientists. It has been proposed that copper carries less toxic, so copper complexes are potential anticancer agents. Infrared and Raman spectroscopic techniques are engaged to obtain vibrational spectra of copper complexes. Also, SERS technique is utilized to explore the interaction of four new copper complexes with guanine or adenine. The findings show that when either cisplatin or carboplatin is added to guanine, the guanine spectral changes within the range of 400 and 1800 frequencies. Moreover, new copper complexes also express the guanine or adenine spectral changes in the same range.Item Synthesis of doxorubicin-protein conjugates via cobalt coordination chemistry: Conjugates of transferrin and immunoglobulin G(11/8/2021) Carvajal de Luna, Juan JoseProtein-drug conjugates are a rapidly expanding family of therapeutics that hold significant potential to ameliorate off-target toxic effects commonly observed in patients undergoing chemotherapy. chemotherapy. In this context, the protein acts as a nanoscale delivery vector that alters the biodistribution of the drug upon administration by restricting its unhindered distribution in vivo. This thesis explores the use of cobalt coordination chemistry in the synthesis of doxorubicin-protein conjugates. Previous work has shown that cobalt can be used to crosslink amine-containing molecules in a reversible reaction that only utilizes the lone pair of electrons on nitrogen to form a dative bond with cobalt. Doxorubicin was chosen for initial studies because it contains a primary amine that could be crosslinked with lysine residues on a protein to form a protein-drug conjugate. Conjugates of dox with albumin, transferrin, and immunoglobulin G were investigated to demonstrate the broad applicability of the method for bioconjugation reactions. Drug loading was investigated by HPLC, and the conjugates further characterized by dynamic light scattering, calorimetry, and cytotoxicity. Details of the effects of reaction conditions on synthesis of stable conjugates will be discussed.Item Utilizing solventless and solvent mediated synthesis of novel coordination polymers based on copper bromide / chloride reactions with cyanopyridines(12/2/2019) Alkhazalah, Reyad Madee; Rawashdeh-Omary, ManalThis thesis covers the following research areas: solvent-mediated, solvent-free synthesis and characterization of copper(I)halides complexes and coordination polymers with various of cyanopyridine ligands, analyzing the photophysical properties, focusing mainly on the luminescence of the copper(I)halides complexes and coordination compounds. It also investigates the impact of structural factors and various synthetic conditions on photophysical properties. This thesis consists of 97 figures, 45 tables, and 125 pages. Eight different compounds have been synthesized in two different synthetic routes; solvent- mediated and solventless with various molar ratio. The characterization of all compounds was done by using elemental analysis, X-ray crystallography, melting point, thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), electronic absorption spectroscopy, and photoluminescence spectroscopy. The analysis for these data will be discussed in this thesis in addition to the potential application of similar compounds in the field of industry.Item Syntheses and characterizations of mixed-ligand copper(I/II) and silver(I) complexes and metallopolymers with pyrazolate- and phenanthroline-based ligands and poly(4-vinylpyridine)(12/2/2019) Kolek, Allan; Rawashdeh-Omary, ManalThis thesis focuses on the syntheses and characterizations of heteroleptic Cu(I/II) and Ag(I) complexes and coordination polymers with fluorinated-pyrazolate (FPz-) and phenanthrolines (phen) ligands, followed by that of copper(I) iodide-based Cu(I/II) complexes and metallopolyers with the fluorinated-pyrazolate (FPz-) ligand and poly(4-vinylpyridine) (PVP). Chapter I provides an introduction into the chemistry of homoleptic coinage metal-pyrazolate complexes, pyrazolate ligands, phenanthroline ligands, heteroleptic coinage metal complexes, solventless syntheses, copper(I) halide complexes, and poly(4-vinylpyridine), respectively, followed by the potential applications of coinage metal complexes/coordination polymers with the aforementioned ligands. Chapter II discusses the synthetic routes of the aforementioned Cu(I/II) and Ag(I) complexes and metallopolymers with the respective ligands. Chapter III discusses structural, physical, and photophysical properties of the resulting products. Chapter IV summarizes and concludes the effects of the different synthetic routes, the metal, and the ligand on the resulting products with regard to their aforementioned properties.Item Investigating the drug mechanism of carboplatin with DNA employing circular dichroism surface-enhanced raman scattering(12/30/2016) Khan, Sidrah; Mirsaleh-Kohan, Nasrin; Rawashdeh-Omary, Manal; Sheardy, Richard DeanItem Tuning chemical and spectroscopic properties of copper and silver cluster complexes upon use of mixed alkylated/fluorinated pyrazolate ligands(12/30/2016) Kohistani, Jehan; Rawashdeh-Omary, Manal; Sheardy, Richard Dean; Johan, Nasrin MisralehItem Mechanism of the ozonation of pyrene ozonide-zwitterion relationships(12/31/1970) Cravy, Betty D.; Sturrock, Murray; Caswell, L.R.; Johnson, James; Davidow, Robert; Wendel, CarltonItem Cadmium distribution and selected tissue histology in rats following administration of cadmium chloride and/or gamma radiation(12/31/1981) Kundomal, Yashdev R.; Hupp, Eugene; Erdman, Howard; Aboul-Ela, Mohammad; Fry, Kenneth; Hines, John; Wendel, CarltonItem Echocardiographic evaluation of a group of obese women(12/31/1981) Elmesallamy, Fatma H.; Rubal, Bernard J.; Fry, Kenneth A.; Aboul-Ela, M. M.Item Synthesis of 1-(2-thienyl) thialkane and attempted synthesis of alkyl substituted thiacyclohexanes(1961-05) Wang, Jean Yii-Chan; Higgins, Robert; Mecay, WilliamIt has been known for some time that the sulfur compounds in petroleum products were both obnoxious and detrimental. Therefore, it was essential that they be removed from the crude petroleum during the refining processes. Unfortunately the removal of the sulfur impurities was not readily accomplished and also was rather costly. Consequently many oil fields containing crudes rich in sulfur have been bypassed. Such extravagances of course could not be continued and petroleum chemists have for many years been in search of better and more economical methods of removing the sulfur impurities. The thought occurred, to those working in this fields that if the chemical structures of the sulfur compounds could be determined, a better method for their removal might be forthcoming. In 1948, the American Petroleum Institute initiated a research project designated as A.P.I. R.P. 40, the purpose of which was to coordinate the work groups and to actually speed up the efforts of the workers involved. The Chemistry staff at the Texas Woman's University became associated with the American Petroleum Institute at the Bureau of Mines in Bartlesville, Oklahoma in 1955, and has been making worthwhile contributions since that time. As reported by previous workers in this laboratory, the method of identification of the sulfur compounds was an indirect one in that the structure was based on a comparison of the chemical and physical properties of the isolated sulfur compounds with the synthetic compounds. If the properties were identical in all cases, it could be assumed that the structures were identical. The primary objective of this research was the preparation of a series of 1-(2-thienyl) thialkanes to serve as reference standards in the search for similar structures in petroleum. The compounds of this type prepared during the course of the investigation were members of two isomeric groups. Namely, 1-(2-thienyl)-3-thialkanes and 1-(2-thienyl)-4thialkanes. The compounds synthesized and sent to the Bureau of Mines at Bartlesville for further study were: 1-(2-thienyl)-3-thia-4-methyl pentane; 1-(2-thienyl)-3-thiahexane; 1-(2-thienyl-3-thia-4-methylhexane; 1-(2-thienyl)-3 thiaheptane; 1-(2-thienyl)-3 thianonane; 1-(2-thienyl)-3-thiadecane; 1-(2-thienyl)-3-thiaundecane; 1-(2-thianyl)-4-thia-5-methylhexane; 1-(2-thienyl)-4 thiaheptane; 1-(2-thienyl)-4-thia-5-methylhexane; 1-(2-thienyl)-4-thiaoctane; 1-(2-thienyl)-4-thiadecane; 1-(2-thienyl)-4-thiaundecane; and 1-(2-thienyl)-4-thiadodecane. A secondary objective of this research was to explore a new synthetic approach to alkylthiacyclohexane derivatives. Previous workers in this laboratory investigated several methods of approach to synthesis of this type but without any appreciable success. The new synthesis involved a Dieckmann condensation of substituted beta thio diesters. Preliminary work has indicated that this approach should be a successful one. It is hoped that investigation will be continued on this synthetic method but unfortunately time did not permit seeing it through to the point of fruition at this time. In view of the fact that the 2-alkylthiophenes seemed to break down in the definite patterns on mass spectral analysis a theoretical aspect of this work was to prepare some deuterated alkylthiophenes. It was hoped that such compounds would be useful in explaining the mechanism of breakdown in the mass spectrometer. During the mass spectral analysis the bond between the alpha and beta carbon atoms apparently ruptured and an olefin was formed. Spectroscopists are interested in accounting for the olefin formation and consequently are concerned as to which hydrogen migrates in the process. Therefore, another objective of this work was the preparation of a 2-alkylthiophene containing a side chain with deutero labeling on specific carbon atoms. Unfortunately, this phase of the work scarcely progressed beyond the planning stage and further work must be carried out. Finally, it should be pointed out that all the compounds prepared were tested by the Microbiological Research Group at the Texas Woman's University for their biological activity. This was done because it was realized that there was a possibility that some of these compounds might have some definite physiological properties which would be of interest and value to mankind.