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Elementary Reactions Involved In Pollutant-Forming Mechanisms, Cheri Ann Mcferrin

LSU Doctoral Dissertations

The reactions of the hydroxyl radical (OH) with molecular chlorine (Reaction 1), methane (Reaction 2), and propane (Reaction 3) have been studied experimentally using a pulsed laser photolysis/pulsed-laser-induced fluorescence technique over wide ranges of temperatures (297-826, 298-1009, and 296-908 K, respectively) and at pressures between 6.68 and 24.15 kPascals. The rate coefficients for these reactions exhibit no dependence on pressure and exhibit positive temperature dependences that can be represented with modified three-parameter Arrhenius expressions within their corresponding temperature ranges: k1 = 3.59 x 10-16T1.35exp(-745K/T)cm3molecule-1sec-1, k2 = 3.82 x 10-19T2.38 exp(-1136K/T)cm3molecule-1sec-1, and k3 = 6.64 x 10-16T1.46 exp(-271K/T)cm3molecule-1sec-1. For the OH …

Synthetic Methods For Biologically Relevant Organofluorine Compounds, Meher Perambuduru

Doctoral Dissertations

"This thesis describes novel synthetic methodologies for the synthesis of biologically relevant organofluorine compounds"--Abstract, page iii.

The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular-level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low-resolution (> 3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (> 200000) techniques such as electrospray ionization (ESI) coupled …

Effects Of Combined Exposure To Ethanol And Ionizing Radiation On The Antioxidant Status Of In Vitro And In Vivo Models, Joshua Ogony

Doctoral Dissertations

"Ethanol and ionizing radiation exposure are independently known to cause tissue damage through various mechanisms. Non-enzymatic and enzymatic metabolism of ethanol, the latter via the cytochrome P₄₅₀2E1-dependent pathway, produces free radicals which deplete cellular glutathione (GSH). Ionizing radiation exposure has been shown to induce lipid peroxidation, DNA damage, protein oxidation, and GSH depletion, as well. It was postulated that initial exposure to ethanol, followed by ionizing radiation, would result in heightened oxidative stress. The in vitro model used in this investigation was HepG2 cells (human hepatocellular liver carcinoma cell line), while the in vivo model was Cd-1 mice"--Abstract, page iii.

Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari

LSU Doctoral Dissertations

Isoporphyrins are tautomers of porphyrins with an interrupted macrocyclic conjugation owing to the presence of a sp3 hybridized meso-carbon. Due to their absorption at long wavelengths (~800nm), isoporphyrins are potential candidates as photosensitizers in photodynamic therapy (PDT), a ternary modality of cancer treatment. They are also of biological interest due to their unique redox properties among porphyrin derivatives and could be a new class of near-IR dyes. Isoporphyrins are known to be unstable with respect to transformation back to the fully conjugated porphyrin chromophore except when the meso-carbon is geminally substituted and for this reason a detailed study of this …

Copper(Ii) Oxide Mediated Formation And Stabilization Of Combustion Generated Persistent Free Radicals, Hieu Truong

LSU Doctoral Dissertations

Biologically damaging semiquinone-type radicals have been reported in cigarette smoke, their likely origin being hydroquinone (HQ) and catechol (CT) molecular precursors contained by the tobacco. Since other biomass contains HQ and CT-type species, it is likely that combustion of other biomass will also form semiquinone-type radicals. All hydrocarbon fuels will form phenol and substituted phenol that can form substituted phenoxyl radicals. Because each of these radicals has the potential to be environmentally persistent and biologically active, their formation and stabilization from various molecular precursors was studied with the focus on surface-bound radicals formed in association with combustion-generated fly-ash particles. Comprehensive …

Use Of Factor Analysis In Multi‐Electron Spectroelectrochemistry, Michael D. Ryan, Robert L. Keesey

Chemistry Faculty Research and Publications

Spectroelectrochemistry and voltammetry contain both unique and complementary information. For multielectron transfers, information on each electron exchange is only directly accessible in the voltammetric data if the potentials are well separated so that two distinct waves can be observed. If the E°’s are close together, the voltammetric data will contain the sum of the two exchanges which can only be deconvoluted by modeling the system and solving the appropriate equations. On the other hand, the spectroscopic data contains direct information on each electron exchange even when the E°’s are close together. Unfortunately, this information cannot be readily extracted if the …

Design Synthesis And Evaluation Of Diterpenones As Potent Chemopreventive Agents For Aflatoxin B1 Induced Carcinogenesis In Human Liver Cells, Miguel Angel Zuniga

Theses and Dissertations

DESIGN, SYNTHESIS, AND EVALUATION OF DITERPENONES AS POTENT CHEMOPREVENTIVE AGENTS FOR AFB1 INDUCED CARCINOGENISIS IN HUMAN LIVER CELLS By Miguel A. Zuniga, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Major Director: Qibing Zhou, Ph.D Assistant Professor Department of Chemistry Terpene quinone methides (TPQMs) have been isolated from a variety of plants and show broad activities against bacteria, fungi, and cancerous cell lines. The biological activity has been attributed to the reactive electrophilic QM moiety, this structural feature has long been recognized as an intermediate in organic …

Structures And Reactivities Of Ionized And Metal Cation-Containing Acetylene Clusters, Paul O. Momoh

Theses and Dissertations

In this dissertation, the ion mobility technique is used to determine the structures of small acetylene cluster ions, (C2H2)1-3+, mass-selected from the largest ever reported ionized acetylene clusters. The technique is also used to characterize the reaction of acetylene clusters with water in an effort to elucidate thermochemistry and kinetics of some interesting ion-molecule reactions suspected to occur in interstellar clouds and other interplanetary bodies.A combination of ion mobility measurements, collision induced dissociation (CID), and theoretical calculations are used to provide the most conclusive evidence for the frequently hypothesized trimerization of ionized acetylene to form the benzene ion. The results …

Initial Studies On A Novel Target-Promoted Dna Alkylation System, Ting Xu

Theses and Dissertations

A novel target-promoted DNA alkylation system was designed, which consists of a DNA intercalating/alkylating quinone methide (QM) precursor, a removable amine linker, and a sequence-specific delivery. The QM in this system was regenerated by eliminating the amino linker promoted by the hydrophobic interaction between the target DNA and the intercalating QM precursor. Three alkylation model systems (methoxyl polycyclic system, intramolecular hydrogen bonding system and biaryl system) were proposed and synthesized. The potential DNA QM alkylation was investigated by deoxyadenosine (dA) and deoxyguanosine (dG) alkylation with the biaryl system. Only one deoxynucleoside adduct was observed when dA or dG reacted with …

Study Of Covalent And Non-Covalent Interactions In Ternary Systems Involving: Metal/Dna-Rna/Protein, Where Metal = Platinum(Ii), Palladium(Ii), Anzellotti I. Atilio

Theses and Dissertations

Ternary systems comprising DNA/RNA, proteins and one (or more) metal ion are generating increased interest due to its biological relevance. The knowledge gained from the study of these systems could provide important clues regarding the precise mechanism for transcription factors, repair proteins and metal complexes with anti-tumoral/anti-viral activities.The interactions occurring among the components of these ternary systems can be broadly grouped into covalent and non-covalent. The first kind of interactions can lead to the irreversible transformation of the components in the system, while the second is thought to be reversible leading to transient states and fluxionality. Both kinds of interaction …

Mechanisms Of Accumulation And Biological Consequences Of Polynuclear Platinum Compounds, Peyman Kabolizadeh

Theses and Dissertations

The novel trinuclear complex, BBR3464 has undergone Phase II clinical trials and been shown to have greater cytotoxicity and cellular uptake than clinical anticancer platinum drugs such as cisplatin, oxaliplatin and carboplatin. The clinical efficacy of cisplatin, oxaliplatin and carboplatin is limited due to acquired resistance and dose limiting side effects. The three major pharmacological factors contributing to the intrinsic cytotoxicity of, and cellular resistance to, platinum drugs are (i) cellular uptake and efflux of platinum; (ii) the frequency and nature of Pt-DNA adducts; and (iii) deactivating metabolic reactions with sulfur-containing nucleophiles. Since decreased cellular uptake of platinum drugs is …

Practical Synthesis Of Unsymmetrical Tetraarylethylenes And Their Application For The Preparation Of [Triphenylethylene−Spacer−Triphenylethylene] Triads, Moloy Banerjee, Susanna J. Emond, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

We have demonstrated that reactions of diphenylmethyllithium with a variety of substituted benzophenones produces corresponding tertiary alcohols that are easily dehydrated, without any need for purification, to produce various unsymmetrical and symmetrical tetraarylethylenes in excellent yields. The simplicity of the method allows for the preparation of a variety of ethylenic derivatives in multigram (10−50 g) quantities with great ease. The methodology was successfully employed for the preparation of various triphenylethylene (TPE)-based triads (i.e., TPE−spacer−TPE) containing polyphenylene and fluoranyl-based spacers. The ready availability of various substituted tetraarylethylenes allowed us to shed light on the effect of substituents on the oxidation potentials …

Borazans:  Tunable Fluorophores Based On 2-(Pyrazolyl)Aniline Chelates Of Diphenylboron, Brendan J. Liddle, Rosalice M. Silva, Tyler James Morin, Felipe P. Macedo, Ruchi Shukla, Sergey V. Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

The reaction between 2-pyrazolyl-4-X-anilines, H(pzAn^X), (X = para-OMe (L1), Me (L2), H (L3), Cl (L4), CO₂Et (L5), CF₃ (L6), CN (L7)) and triphenylboron in boiling toluene affords the respective, highly emissive N,N‘-boron chelate complexes, BPh₂(pzAn^X) (X = para-OMe (1), Me (2), H (3), Cl (4), CO₂Et (5), CF₃ (6), CN (7)) in high yield. The …

Chemistry And Biology Of Streptogramin A Antibiotics, Fahim Ahmed, William A. Donaldson

Chemistry Faculty Research and Publications

The streptogramin A antibiotics have proven to be highly active against Gram positive bacteria, particularly methicillin-resistant Staphylococcus aureus. Members of this group of compounds are characterized by a 23-membered macrocycles containing polyene, oxazole, amide and ester functionality. The chemistry and biology of these valuable antimicrobial agents is covered.

Conserved Amino Acids In Each Subunit Of The Heteroligomeric Trna M1A58 Mtase From Saccharomyces Cerevisiae Contribute To Trna Binding, Sarah G. Ozanick, Janusz M. Bujnicki, Daniel S. Sem, James T. Anderson

Chemistry Faculty Research and Publications

In Saccharomyces cerevisiae, a two-subunit methyltransferase (Mtase) encoded by the essential genes TRM6 and TRM61 is responsible for the formation of 1-methyladenosine, a modified nucleoside found at position 58 in tRNA that is critical for the stability of . The crystal structure of the homotetrameric m¹A58 tRNA Mtase from Mycobacterium tuberculosis, TrmI, has been solved and was used as a template to build a model of the yeast m¹A58 tRNA Mtase heterotetramer. We altered amino acids in TRM6 and TRM61 that were predicted to be important for the stability of the heteroligomer based on …

Preparation, Characterization And Reactivity Of (3-Methylpentadienyl)Iron(1+) Cations, Subhabrata Chaudhury, Shukun Li, Dennis W. Bennett, Tasneem Siddiquee, Daniel T. Haworth, William A. Donaldson

Chemistry Faculty Research and Publications

The title cations (9 and 12) were prepared by dehydration of (3-methyl-2,4-pentadien-1-ol)Fe(CO)₂L⁺ complexes. The structure of the (CO)₂PPh₃-ligated 12 was determined by single-crystal X-ray analysis. Reaction of carbon and heteroatom nucleophiles to (3-methylpentadienyl)Fe(CO)₃⁺ cations 9 and 12 proceeds either via attack at the dienyl terminus to give (3-methyl-1,3Z-diene)iron complexes or via attack at the internal carbon, followed by carbon monoxide insertion and reductive elimination to afford 3-methyl-4-substituted cyclohexenones. Cyclohexenone formation was found to be prevalent for addition of stabilized nucleophiles with strongly dissociated counterions to cation 9 …

Antibacterial Fluoromicas: A Novel Delivery Medium, Bekir Dizman, Jonathan C. Badger, Mohamed O. Elasri, Lon J. Mathias

Faculty Publications

Antibacterial fluoromicas were prepared by ion-exchanging fluoromicas with different antibacterial agents including various quaternary ammonium compounds, AgNO₃, and norfloxacin. Antibacterial activities of the ion-exchanged fluoromicas were determined against Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) tests were performed to determine both antibacterial effectiveness and mode of action associated with the fluoromicas. All treated fluoromicas showed excellent antibacterial activities against both types of bacteria. The antibacterial activities of treated fluoromicas were found to be either better than or the same as those of neat antibacterial agents. The repeated antibacterial activity tests demonstrated …

Constituents Of Nepeta Crassifolia (Lamiaceae), Syed Amir Ibrahim, Muhammad Shaiq Ali

Turkish Journal of Chemistry

A long chain ketone (crassifone), a pentacyclic triterpenoid coupled with fatty acid moiety (crassifoate), and an acyclic diterpenoid (crassifol) have been isolated from the ethanol soluble part of Nepeta crassifolia (Lamiaceae) collected from Kangavar, Iran. Structures of all the metabolites were elucidated with the aid of spectroscopic techniques, including 2D NMR experiments.

The Direct Electrochemical Synthesis Of Ti(Ii), Fe(Ii), Cd(Ii), Sn(Ii), And Pb(Ii) Complexes With N, N´-Bis(Salicylidene)-O-Phenylenediamine, Jianning Liu, Bing Zhang, Bowan Wu, Kejun Zhang, Shenli Hu

Turkish Journal of Chemistry

The electrochemical oxidation of anodic Ti, Fe, Cd, Sn, and Pb (=M) into acetonitrile solutions of N,N'-bis(salicylidene)-o-phenylenediamine [SalophH_2] gives the corresponding M(Saloph) complexes in high yield. The mechanism of the electrochemical reactions is discussed. SalophH_2 forms complexes (1:1 molar ratio) with titanium, iron, cadmium, tin, and lead ions. The complexes have been characterized by elemental analyses, molar conductivity measurements, and infrared and electronic spectral data. The SalophH_2 complexes of iron(II) and cadmium(II) have been further identified by ^1H-NMR and mass spectra.

Chemoenzymatic Synthesis Of 2-Bromo-6-Hydroxy-3-Methoxy-2-Cyclohexen-1-One, Emi̇ne Özgül Karaaslan, Yasemi̇n Toka

Turkish Journal of Chemistry

A chemoenzymatic synthesis of 2-bromo-6-hydroxy-3-methoxy-2- cyclohexen-1-one starting from cyclohexane-1,3-dione is reported. Manganese(III) acetate-mediated acetoxylation followed by the enzyme-mediated hydrolysis of \alpha'-acetoxy enone affords hydroxy-enone 5 and acetoxy enone 4 with high enantiomeric excesses in good yields.

Investigation Of The Voltammetric Characteristics Of Poly(1,4-Diaminobenzene) Film As A Dopamine-Selective Polymer Electrode, Gamze Erdoğdu, A. Ersi̇n Karagözler

Turkish Journal of Chemistry

Electrochemical polymerization of 1,4-diaminobenzene in the KCl aqueous electrolyte at a potential of 0.600 V versus Ag/AgCl produces adherent poly(1,4-diaminobenzene) film on a gold electrode. The electrochemical behavior of dopamine and ascorbic acid at the polymer electrode prepared in this manner was examined by cyclic and differential pulse voltammetry. Voltammetry studies showed that polymeric film with a thickness corresponding to a 7-mC charge exhibited selective permeation for dopamine while retaining ascorbic acid. All the polymerization parameters affecting the permselective characteristics were systematically investigated and the optimum values were determined. The results showed that a polymeric membrane, owing to its permselective …

A New Approach To Furan-Containing Macrolactones, Christoph Schmidt, Ruth Messmer, Franz Bracher, Jurgen Krauss

Turkish Journal of Chemistry

Furan and tetrahydrofuran heterocycles are part of many natural products, like the Galerucella pheromone, furano epothilones, bipinnatin, and amphidinolides. This paper describes a short and efficient synthetic approach to furan-containing macrolactones in 4 steps, including as key steps a Sonogashira reaction and an olefin metathesis. The resulting compounds were tested at the National Cancer Institute for their cytotoxicity, but did not exhibit significant cytotoxicity in the human tumour cell line screen.

Mono-, Di- And Trinuclear Copper(Ii) Complexes Of A Schiff Base Ligand, 2-{(E)-[(6-{[(1e)-(2-Hydroxyphenyl)Methylene]Amino}Pyridin-2-Yl)Imino]-Methyl}Phenol, Nevi̇n Karaböcek, Serdar Karaböcek, Fatma Kormali

Turkish Journal of Chemistry

A Schiff base ligand, 2-{(E)-[(6-[(1E)-(2-hydroxyphenyl) methylene]amino}-pyridin-2-yl)imino]-methyl} phenol (H_2PySAL), was prepared by condensation of 2,6-diaminopyridine and salicylaldehide in EtOH. The Schiff base ligand was checked by elemental analyses, ^1H-NMR, ^{13}C-NMR, IR, UV/Vis, and mass spectral studies. Three new mono-, di-, and trinuclear copper(II) complexes of the Schiff base ligand, formula [Cu(H_2PySAL)]Cl_2, [Cu_2(PySAL) (Phen)]Cl_2, [Cu_3(PySAL)_2]Cl_2, were prepared and characterized by elemental analyses, magnetic moment, and IR, Uv/Vis, and mass spectral studies. The spectroscopic data of the complexes indicate that the copper(II) ions are coordinated by the oxygen atoms and nitrogen atoms (C=N) of the ligand. In the dinuclear complex, in which the …

Synthesis Of Some New 1-Acylthiosemicarbazides And 1,2,4-Triazol-5-Thiones, And Their Analgesic And Anti-Inflammatory Activities, Yasemi̇n Dündar, Bi̇lge Çakir, Esra Küpeli̇, M. Fethi̇ Şahi̇n, Ni̇ngur Noyanalpan

Turkish Journal of Chemistry

We synthesized new 1-[3-(2-oxobenzothiazolin-3-yl)propanoyl]-4- substituted-thiosemicarbazides and their corresponding cyclized 3-[2-(2-oxobenzothiazoline-3-yl)ethyl]-4-substituted-1,2,4-triazol-5-thione ana-logs in which position 4 of the triazole ring was substituted by cyclohexyl, methyl, allyl, phenyl, p-methylphenyl, p-methoxyphenyl, p-chlorophenyl, p-nitrophenyl, benzyl, and phenylethyl to screen their analgesic and anti-inflammatory activities as well as gastric ulceration potential in test animals. None of the compounds, except 5a, 5e, and 5h, caused gastric lesions or bleeding. Compound 5g was found to have higher analgesic and anti-inflammatory activity among the synthesized compounds.

Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nurhan Gümrükçüoğlu, Mevlut Serdar, Eli̇f Çeli̇k, Ali̇ Sevi̇m, Nesli̇han Demi̇rbaş

Turkish Journal of Chemistry

A series of acylhydrazones (2a-f) were synthesized by the condensation of iminoester hydrochlorides (1a-f) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a,c,e) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3,5-dialkyl-1,2,4-triazoles produced N-[3,5-dialkyl-4H-1,2,4-triazol-4-yl] acetamides (5-7). The treatment of compounds 4a and 4c with various aromatic aldehydes resulted in the formation of 4-arylidenamino-3,5-dialkyl-1,2,4-triazoles (8a,d, e, and 10a-e). Sodium borohydride reduction of 4-arylidenamino derivatives afforded 4-alkylamino-3,5-dialkyl-1,2,4-triazoles (9a,d, e, and 11a-e). Compounds 4b, 4c, 7, 8d, and 11c showed good antifungal activity only against yeast-like fungi, while compounds 3e, 6, 8e, and 9e …

Synthesis, Spectroscopic Investigation, Crystal Structure, And Biological Screening, Including Antitumor Activity, Of Organotin(Iv) Derivatives Of Piperonylic Acid, Muhammad Hanif, Mukhtiar Hussain, Saqib Ali, Moazzam H. Bhatti, Muhammad Sheeraz Ahmed, Bushra Mirza, Helen S. Evans

Turkish Journal of Chemistry

We prepared 8 new organotin compounds with the general formulae [R_3SnL], where R = Me (1), Bu (2), Ph (3), and Cy (4) and [R_2SnL_2], where R = Me (5), Et (6), Bu (7), Oct (8), and L = piperonylic acid, and characterized them by elemental analyses, IR spectra, and multinuclear NMR (^1H, ^{13}C, and ^{119}Sn). The structure of 5 was confirmed by single crystal X-ray crystallography. The geometry around the tin atom was compared in both solution and solid state. Crystals of 5 are monoclinic with the space group P2_1/c. The tin geometry is skew trapezoidal bipyramidal, with 2 …

Kinetic Studies Of The Hydrolysis Reactions Of Ruthenium (Iii) Complexes Him Trans-[Rucl₄(Im)₂] And Hind Trans-[Rucl₄(Ind)₂] By Uv-Visible Spectrophotometry, Pramod K. Nangunuri

Master's Theses and Doctoral Dissertations

The ruthenium complexes have gained importance in cancer research in recent times, as several cancers have developed resistance towards platinum compounds. Platinum compounds have severe adverse effects that limited their use towards a wide range of tumors.

Ruthenium complexes are considered as pro-drugs, as they transform into antitumor active species in the body by hydrolysis, redox reactions, and reactions with biologically occurring nucleophiles. My project involved the synthesis of two ruthenium complexes with different ligands and the study of the hydrolysis reactions under different pH at room temperature using UV-visible spectrophotometry.

These studies will enable us to understand how structural …

Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani

LSU Doctoral Dissertations

The association mechanism between hydrophobic organic compounds (HOC) and dissolved humic materials (DHM) has continued to be one of the interesting areas in environmental applications. The goal of the research reported in this dissertation is to investigate the association behavior of HOC with DHM. The first part of this research involves steady-state fluorescence measurements of these multi-component systems to study the effect of DHM content on the association mechanism of HOC, in particular using pyrene as a model. Results showed that steady-state fluorescence alone may not provide enough information about the quenching mechanism of pyrene with DHM. Lifetime based fluorescence …

Stereochemical And Regiochemical Trends In The Selective Spectrophotometric Detection Of Biological Molecules, Shan Jiang

LSU Doctoral Dissertations

Useful mechanistic studies to date concerning sugar detection by arylboronic acid chemosensors have mainly involved the elucidation of equilibrium constants and the role of boron-nitrogen interactions in signal transduction. However, several discreet sugarboronate complexes exist in solution. This is due to the complex equilibria between isomeric species of even the simplest monosaccharides. Relatively few reports have been devoted to a systematic study of the structures of each of the corresponding individual sugar-boronate complexes. We have investigated some of the precise regio- and stereochemical features of the various equilibrating sugar isomers that induce selective signal transduction. As a result of this …