Digital Commons Network^™

Investigation Of Electron Transfer Reaction Between Diphenylbenzidine And Ascorbic Acid, Iftikhar Imam Naqvi, Abida Perveen

Turkish Journal of Chemistry

The kinetics of the reduction of diphenylbenzidine by ascorbic acid were investigated in the pH range 3.5 to 5.0. Diphenylbenzidine was prepared by the oxidation of diphenylamine with cerium(IV) sulfate tetra hydrate. The order of the reaction with respect to each of the reactants, i.e ascorbic acid (ASC), diphenylbenzidine (DPB) and H^+ ,was found to be first. The following rate law is recommended: Rate = {k_1 [C_{12}H_{10}N_2C_{12}H_{10}] + k_2K [C_{12}H_{10}N_2C_{12}H_{10}][H^+]}[C_6H_8O_6] where k_1 and k_2 have the values of 2.0 \times 10^4 dm^3mol^{-1} s^{-1} and 6.58 \times 10^3 dm^3.mol^{-1}.s^{-1} , respectively. K is the protonation constant of DPB, having a value …

Synthetic Studies In Phytochrome Chemistry, Peter A. Jacobi, Imad Odeh, Subhas Buddhu, Guolin Cai, Sundaramoorthi Rajeswari, Douglas Fry, Wanjun Zheng, Robert W. Desimone, Jiasheng Guo, Lisa D. Coutts, Sheila I. Hauck, Sam H. Leung, Indranath Ghosh, Douglas Pippin

Dartmouth Scholarship

An account is given of the author’s several approaches to the synthesis of the parent chromophore of phytochrome (1), a protein-bound linear tetrapyrrole derivative that controls photomorphogenesis in higher plants. These studies culminated in enantioselective syntheses of both (2R)- and (2S)-phytochromobilin (4), as well as several ¹³C-labeled derivatives designed to probe the site of Z,E-isomerization during photoexcitation. When reacted in vitro, synthetic 2R-4 and recombinant-derived phytochrome apoprotein N-C produced a protein-bound chromophore with identical difference spectra to naturally occurring 1.

A General Synthesis Of Tris-Indole Derivatives As Potential Iron Chelators, R. Bryan Sears, Russell A. Carpenter, Christine R. Whitlock

Chemistry: Faculty Publications (1990-2023)

The development of a novel route for the synthesis of a new class of compounds is described. The first tripodal, tris-indole amines are prepared by straightforward routes.

Detection Of Biologically Important Molecules, Kyukwang Kim

LSU Doctoral Dissertations

Anions play important roles in biological systems. The design of anion sensors has been of great interest. The selective detection of a specific anion is particularly challenging. In the first chapter, I describe the synthesis of a TBS-protected fluorescein dye (1.1) and its use for the selective detection of fluoride. Solutions of 1.1 either in DCM or in aqueous media at physiological pH show the excellent selectivity towards fluoride to afford color formation while solutions of other interfering anions remain colorless. The monitoring of homocysteine (Hcy) and cysteine (Cys) levels is important since they are biomarkers associated with Alzheimer’s and …

A Regularized And Renormalized Electrostatic Coupling Hamiltonian For Hybrid Quantum-Mechanical–Molecular-Mechanical Calculations, Pradip K. Biswas, Valentin Gogonea

Chemistry Faculty Publications

We describe a regularized and renormalized electrostatic coupling Hamiltonian for hybrid quantum-mechanical (QM)–molecular-mechanical (MM) calculations. To remedy the nonphysical QM/MM Coulomb interaction at short distances arising from a point electrostatic potential (ESP) charge of the MM atom and also to accommodate the effect of polarized MM atom in the coupling Hamiltonian, we propose a partial-wave expansion of the ESP charge and describe the effect of a s-wave expansion, extended over the covalent radius rc, of the MM atom. The resulting potential describes that, at short distances, large scale cancellation of Coulomb interaction arises intrinsically from the localized expansion of the …

Messenger Rna Profiling: A Prototype Method For Body Fluidand Tissue Identification, Jane Juusola

Electronic Theses and Dissertations

Conventional methods of body fluid identification use labor-intensive, technologically diverse techniques that are performed in a series, not parallel, manner and are costly in terms of time and sample. Furthermore, for some frequently encountered body fluids, such as saliva or vaginal secretions, no confirmatory technique exists. Terminally differentiated cells, such as blood lymphocytes or epithelial cells lining the oral cavity, have a unique pattern of gene expression, which is evinced by the presence and relative abundance of specific mRNA species. If the type and abundance of mRNAs can be determined in a stain or tissue sample recovered at the crime …

Synthesis, Characterizations, And Evaluation Of New Reactive Two-Photon Absorbing Dyes For Two-Photon Excited Fluorescence Imaging Applications, Katherine J. Hales

Electronic Theses and Dissertations

Recent, cooperative advances in chemistry, biology, computing, photophysics, optics, and microelectronics have resulted in extraordinary developments in the biological sciences, resulting in the emergence of a novel area termed 'biophotonics'. The integrative and interdisciplinary nature of biophotonics cuts across virtually all disciplines, extending the frontiers of basic cellular, molecular, and biology research through the clinical and pharmaceutical industries. This holds true for the development and application of the novel imaging modality utilizing multiphoton absorption and its extraordinary contribution to recent advances in bioimaging. Intimately involved in the revolution of nonlinear bioimaging has been the development of optical probes for probing …

Punishment And Rehabilitation Views Of Social Work Majors And Non-Social Work Students: An Exploratory Study, Eric G. Lambert, Sudershan Pasupuleti, Reva I. Allen

Journal of the South Carolina Academy of Science

No abstract provided.

Design And Cloning Of A Hammerhead Ribozyme Targeted Tohiv-1p7fmrna, Katherine L. Anderson, William H. Jackson

Journal of the South Carolina Academy of Science

No abstract provided.

Molecular Dynamics Simulations Of Amphiphilic Molecules, Roger L. Mcmullen Jr.

Seton Hall University Dissertations and Theses (ETDs)

.

Synthesis Of Novel Porphyrazines And Binding Studies To Dna Quadruplexes, Carlos Ramirez

Seton Hall University Dissertations and Theses (ETDs)

.

Synthesis Of Pyrrolidines And Pyrrolizidines Using The Aza-Cope Rearrangement Mannich Cyclization Under Microwave Conditions, Amanda Schalk

Senior Honors Theses and Projects

No abstract provided.

Determination Of Trifluoroacetate By Ion Chromatography For Snow And Ice Analysis, Jon Hanson

The Journal of Undergraduate Research

Trifluoroacetic acid (TEA) is a product of the atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). HCFCs and HFCs are widely used substitutes for chlorofluorocarbons (CFCs) that have been found to contribute to the loss of stratospheric ozone. Deposits of TEA with precipitation (rain and snow) can lead to its presence and accumulation in the aquatic and cryosphere environments, with unknown long-term environmental consequences. Investigation on TEA impact and its fate in the environment requires sensitive, accurate, and fast analytical methods. The determination of trace concentrations of TEA using the technique of ion chromatography (IC) is investigated in this study, …

Part I : Isolation Of Dipentyl 2-(4-(Pentan-3-Yl) Phenyl) Malonate From Sanguisorba Officinalis Labill Part Ii: Synthesis Of A Novel Family Of Ethers Of Podocarpic Acid, Manjeera Yalavarty

Electronic Theses and Dissertations

The goal of part I of this thesis was to isolate pure anti cancer compounds from the Russian plant Sanguisorba officinalis. This plant was selected for investigation because it showed 100% activity against leukemia (L1210 mouse leukemia cells) during the preliminary screening of approximately 100 Russian plant extracts. This work has resulted in the isolation of novel compound 11 using traditional chromatography techniques. Compound 11 was characterized with spectroscopic techniques such as IR, 1H NMR, 13C NMR, DEPT, DQCOSY and MS. Compound 11 was assigned the structure dipentyl 2-(4-(pentan-3-yl) phenyl) malonate. The goal of part II of this thesis was …

Naturally-Derived Porphyrin And Chlorin Photosensitizers For Photodynamic Therapy, Jodie Angela Hargus

LSU Master's Theses

In oncologic applications of photodynamic therapy (PDT), the discriminating localization of porphyrin-type compounds in solid tumors is exploited for the selective ablation of neoplastic tissue with minimal destruction and irritation to normal tissue. PDT is a locoregional, binary cancer therapy in which a photosensitizer—light-activated drug—absorbs light of an appropriate wavelength and excites to the singlet state. This photosensitizer in the excited singlet state can undergo an internal transition to the excited triplet state, a relatively long-lived and high-energy species that transfers its excess energy to molecular oxygen. Molecular oxygen subsequently excites from the stable triplet state to the highly reactive …

The Importance Of Size And Shape In Imprinted Polymers, Jason Campbell

LSU Master's Theses

The existence of shape selectivity in non-covalent molecularly imprinted polymers has been proven using molecular probes. A series of amines varying with different structural motifs and secondary amines with different sized side chains were imprinted, and binding evaluated by HPLC for each amine on polymers imprinted with similar amines. Trends in the binding relationships revealed two major contributions of cavity structure on selectivity afforded by molecularly imprinted polymers (MIPs). First, sterics play a dominant role in cases where a molecules structure is too big too fit into an imprinted site formed from a smaller template molecule. Second, molecular structures that …

Novel Cyanine-Amp Conjugates For Efficient 5' Rna Fluorescent Labeling By One-Step Transcription And Replacement Of [γ-32P] Atp In Rna Structural Investigation, Na Li, Changjun Yu, Faqing Huang

Faculty Publications

Two novel fluorescent cyanine-AMP conjugates, F550/570 and F650/670, have been synthesized to serve as transcription initiators under the T7 φ2.5 promoter. Efficient fluorophore labeling of 5′ RNA is achieved in a single transcription step by including F550/570 and F650/670 in the transcription solution. The current work makes fluorescently labeled RNA readily available for broad applications in biochemistry, molecular biology, structural biology and biomedicine. In particular, site-specifically fluorophore-labeled large RNAs prepared by the current method may be used to investigate RNA structure, folding and mechanism by various fluorescence techniques. In addition, F550/570 and F650/670 may replace [γ-³²P]ATP to prepare …

Near-Edge X-Ray Absorption Fine Structure Study Of Ion-Beam-Induced Phase Transformation In Gd2(Ti1-Yzry)2o7, Ponnusamy Nachimuthu, S. Thevuthasan, V. Shutthanandan, E. M. Adams, W. J. Weber, B. D. Begg, D. K. Shuh, Dennis W. Lindle, Eric M. Gullikson, Rupert C. Perera

Chemistry and Biochemistry Faculty Research

The structural and electronic properties of Gd₂(Ti_1−yZr_y)₂O₇ (y=0–1) pyrochlores following a 2.0-MeV Au²⁺ ion-beam irradiation (~5.0 X 10¹⁴ Au²⁺/cm²) have been investigated by Ti 2p and O 1s near-edge x-ray absorption fine structure (NEXAFS). The irradiation of Gd₂(Ti_1−yZr_y)₂O₇ leads to the phase transformation from the ordered pyrochlore structure (Fd3m) to the defect fluorite structure (Fm3m) regardless of Zr concentration. Irradiated Gd₂(Ti_{1−y …}

Fragmentation Dynamics Of H2s Following S 2p Photoexcitation, Renaud Guillemin, S-W Yu, Wayne C. Stolte, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

The fragmentation dynamics of core-excited H₂S has been studied by means of partial anion and cation yield measurements around the S L_2,3-subshell ionization thresholds. All detectable ionic fragments are reported, and significant differences between partial ion yields are observed. Possible dissociation pathways are discussed by comparison to previous studies of electron spectra.

Determination Of Trace Copper By Faas After Solid Phase Extraction And Preconcentration Onto Amberlite Xad-2 Loaded With Nitroso-R Salt, Mohammad Ali Taher, Sayed Ziae Mohammadi Mobarakeh, Ali Reza Mohadesi

Turkish Journal of Chemistry

A procedure for the separation and preconcentration of trace amounts of copper is proposed. It is based on the adsorption of copper(II) ions solution onto a column of Amberlite XAD-2 resin loaded with disodium 1-nitroso-2-naphthol-3, 6-disulfonate (nitroso-R salt). Copper is quantitatively retained on the column in the pH range 5.5-7.8 at a flow rate of 2 mL min^{-1}. The copper complex eluted with 5 mL of dimethylformamide (DMF) and copper was measured by flame atomic absorption spectrometry (FAAS) at 324.8 nm. In this case, 0.10 \mu g of copper can be concentrated in the column from 800 mL of aqueous …

Synthesis, Spectral And Thermal Investigations Of Some Oxovanadium(Iv) Complexes Of Hydrazones Of Isonicotinic Acid Hydrazide, Ram K. Agarwal, Lakshman Singh, Deepak K. Sharma, Ritu Singh

Turkish Journal of Chemistry

A new series of 12 complexes of oxovanadium(IV) with hydrazones of isonicotinic acid hydrazide, namely N-isonicotinamido-3',4',5'-trimethoxybenzalaldimine (INH-TMB) and N-isonicotinamido-2'-furanaldimine (INH-FUR) with the general formula VOX_2.nL (X = Cl, Br, I, NCS, NO_3, n = 1; X = ClO_4, n = 2; L = INH-TMB or INH-FUR) were synthesized and characterized on the basis of analytical, conductance, molecular weight, magnetic moment, infrared and electronic spectral data. The infrared data of the complexes reveal the bidendate nature of both ligands and coordination to carbonyl-oxygen and azomethinic-nitrogen atoms. The probable coordination number of the central metal is 5. Thermal stabilities of the complexes …

Studies Of Unusual Packing And Of Polymorphism In Two Crystal Systems, Xiang Hao

University of Kentucky Doctoral Dissertations

Crystal structures of anhydrous pinacol, the hexagonal pinacol, pinacol monohydrate, and pinacol hexahydrate were studied. In all the structures crystal packing is unusual and complicated. The origin of the complexity may be the difficulty in filling space densely and while also satisfying the H-bonding requirements when the molecule has few internal degrees of freedom.

Five 15-crown-5 complexes of M(NO₃)₂ (M = Cu, Zn, Mg, Co, Mn) were synthesized and characterized using X-ray diffraction and differential scanning calorimetry. The system is rich in polymorphs. Nine definite solid-state phases were identified. More phases probably exist in the solid state …

Crystal Structure Of The Gtpase Domain Of Rat Dynamin 1, Thomas F. Reubold, Susanne Eschenburg, Andreas Becker, Marilyn Leonard, Sandra L. Schmid, Richard B. Vallee, F. Jon Kull, Dietmar J. Manstein

Dartmouth Scholarship

Here, we present the 1.9-A crystal structure of the nucleotide-free GTPase domain of dynamin 1 from Rattus norvegicus. The structure corresponds to an extended form of the canonical GTPase fold observed in Ras proteins. Both nucleotide-binding switch motifs are well resolved, adopting conformations that closely resemble a GTP-bound state not previously observed for nucleotide-free GTPases. Two highly conserved arginines, Arg-66 and Arg-67, greatly restrict the mobility of switch I and are ideally positioned to relay information about the nucleotide state to other parts of the protein. Our results support a model in which switch I residue Arg-59 gates GTP binding …

Synthesis Of Alkylthiol-Containing Fluorene Derivatives For Gold Nanoparticle Functionalization, Sriram Mukundarajan

Electronic Theses and Dissertations

A novel synthetic methodology has been developed for attaching fluorene derivatives, containing different types of electron donating and accepting groups at the 2 and 7 positions, to gold nanoparticles of different sizes by exploiting the affinity of the thiol functional group for gold. The distance between the dye and nanoparticles was varied by introducing two alkyl chains containing different number of carbon atoms at the 9 position on the fluorene ring system. The methodology that was developed gave enough scope for performing Radiative Decay Engineering (RDE) studies, in order to investigate the impact of gold nanoparticles on the singlet oxygen …

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H₂O₂ photoproduction. The H_{2 …}

Assessment Of Rarity Of The Blackmouth Shiner Notropis Melanostomus (Cyprinidae) Based On Museum And Recent Survey Data, Martin O'Connell

Earth and Environmental Sciences Faculty Publications

Accurate knowledge of an organism's distribution is necessary for conserving species with small or isolated populations. A perceived rarity may only reflect inadequate sampling effort and suggest the need for more research. We used a recently developed method to evaluate the distribution of a rare fish species, the blackmouth shiner Notropis melanostomus Bortone 1989 (Cyprinidae), which occurs in disjunct populations in Mississippi and Florida. Until 1995, N. melanostomus had been collected from only three localities in Mississippi, but in 1995, eight new localities were discovered. We analyzed museum records of fish collections from Mississippi, Florida, and Alabama to compare sampling …

Assessment And In Vitro Repair Of Damaged Dna Templates From Forensic Stains, Ashley Hall

Electronic Theses and Dissertations

DNA extracted from biological stains is often intractable to analysis. This may due to a number of factors including a low copy number (LCN) of starting molecules, the presence of soluble inhibitors or damaged DNA templates. Remedies may be available to the forensic scientist to deal with LCN templates and soluble inhibitors but none presently exist for damaged DNA. In fact, only recently has the biochemical nature, the extent of DNA damage in physiological stains and the point at which the damage inflicted upon a particular sample precludes the ability to obtain a genetic profile for purposes of identification been …

Synthesis And Nmr-Characterization Of Three Quinamide-Based Disaccharide Mimetics With Unusual Cyclohexane Twist-Conformation, Thuy Trang M. Nguyen, Paul H. Gross, Andreas H. Franz

College of the Pacific Faculty Articles

The synthesis of amide-linked disaccharide mimetics has been explored starting with carbohydrate-based amines and a protected quinic acid lactone. Benzyl-2-amino-4,6-Obenzylidene-2-deoxy-α/β-D-glucopyranose (12) and D-glucamine (14) were successfully coupled to give the corresponding quinamides (13 and 15), while the quinoylation of Oacetylated L-fucopyranosyl methylamine (7) failed. The latter was prepared from per-O-acetylL-fucopyranose via the improved multigram scale synthesis of the corresponding per-O-acetylL-fucopyranosyl cyanide (3). Compound 3 was subsequently hydrogenated to yield a mixture of compound 7 and the per-O-acetylated bis-(fucopyranosylmethyl) amine (5). The vicinal coupling constants in the NMR spectra of all quinamide products revealed considerable flexibility of the cyclohexane ring in …

Bismuth Triflate Catalyzed Friedel-Crafts Acylations Of Sydnones, Jennifer Ann Fisher

Browse all Theses and Dissertations

In the present work, suitably functionalized arylsydnones were used to synthesize a variety of 4-acylsydnones and diacyl sydnones, both as potential precursors to novel sydnoquinolines.The approach to the diacyl species is based on the discovery that activated sydnonesbrominate in both the 4 position of the sydnone ring and on the phenyl ring. Thus, it seemed likely that Friedel-Crafts reactions on an activated sydnone would give diacylated species for McMurray coupling to sydnoquinolines. Friedel-Crafts acylations on the 4 position of the sydnone ring have been achieved in high yields using 4 equivalents of various alkyl anhydrides, 25 mol % of bismuth …

Analytical Tools For Studying Phosphorus And Nitrogen Lake Nutrient Dynamics And Their Application To The Field, Ivan Mihajlov

Honors Theses

In order to evaluate the causes and conditions that lead to cyanobacteria blooms in northern temperate lakes, studies of nutrients such as total phosphorus, total nitrogen, phosphate, and nitrate are necessary. Sensitive, environmentally friendly and cost-effective techniques were developed to detect ppb-level nitrates and phosphates in the lake water. Phosphate was analyzed by luminol chemiluminescence, while the quantification of nitrate was performed by capillary electrophoresis (CE) using indirect UV detection, with a background electrolyte consisting of pyromellitic acid, hexamethonium hydroxide and triethanolamine. Sample injection methods for the CE were optimized for the analysis in Belgrade Lakes, Maine. Vertical profiles of …