Chemistry Commons^™

Cloning, Expression, And Purification Of Glyoxysomal 3-Oxoacyl-Coa Thiolase From Sunflower Cotyledons, Anke C. Schiedel, Silke Oeljeklaus, Patricia Minihan, Jim Dyer

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The glyoxysomal β-oxidation system in sunflower (Helianthus annuus L.) cotyledons is distinguished by the coexistence of two different thiolase isoforms, thiolase I and II. So far, this phenomenon has only been described for glyoxysomes from sunflower cotyledons. Thiolase I (acetoacetyl-CoA thiolase, EC 2.3.1.9) recognizes acetoacetyl-CoA only, while thiolase II (3-oxoacyl-CoA thiolase, EC 2.3.1.16) exhibits a more broad substrate specificity towards 3-oxoacyl-CoA esters of different chain length. Here, we report on the cloning of thiolase II from sunflower cotyledons. The known DNA sequence of Cucumis sativus 3-oxoacyl-CoA thiolase was used to generate primers for cloning the corresponding thiolase from sunflower cotyledons. …

Enhanced Resonant Soft X-Ray Scattering Yba2cu3o7-X 50 Nm Thin Films On Bycristalline Substrates, M. Navacerrada, H. Sahibudeen, Jeffrey Kortright, Juana Acrivos

Faculty Publications, Chemistry

No abstract provided.

Relation Between Increased Transmision In Xas And Increase In Abrikosov Vortices As T→Tc, J. Chigvinadze, G. Mamniashvilli, Juana Acrivos

Faculty Publications, Chemistry

The increased transmission, observed in the EXAFS region of their X-ray absorption spectra, as cuprate materials go through the superconducting transition temperature Tc is correlated with a critical increase in Abrikosov Vortex expulsion in zero magnetic field as the temperature T →Tc.

Distributions Of Z-Dna And Nuclear Factor I In Human Chromosome 22: A Model For Coupled Transcriptional Regulation, P. Christoph Champ, Sandor Maurice, Jeff Vargason, Tracy Camp, P. Shing Ho

Faculty Publications - Department of Biological & Molecular Science

An analysis of the human chromosome 22 genomic sequence shows that both Z-DNA forming regions (ZDRs) and promoter sites for nuclear factor-I (NFI) are correlated with the locations of known and predicted genes across the chromosome and accumulate around the transcriptional start sites of the known genes. Thus, the occurrence of Z-DNA across human genomic sequences mirrors that of a known eukaryotic transcription factor. In addition, 43 of the 383 fully annotated chromosomal genes have ZDRs within 2 nucleosomes upstream of strong NFIs. This suggests a distinct class of human genes that may potentially be transcriptionally regulated by a mechanism …

Development Of A Gene Transfer System In Clostridium Scindens Vpi 12708, Rashmi Ramasubbaiah

Masters Theses & Specialist Projects

Clostridium scindens VPI 12708 (previously known as Eubacterium sp. VPI 12708) is a bile-acid dehydroxylating bacterium originally isolated from the feces of a colon cancer patient. Many genes required for bile acid 7-a dehydroxylation are found on a large bile acid inducible operon (bai) that has been extensively studied. However the bai promoter, which directs expression of the bai operon, has yet to be characterized due, in part, to a lack of a functional genetic transfer system for this strain. A spontaneous rifampinresistant Clostridium scindens VPI 12708 mutant was used as a recipient to determine the efficacy of conjugation as …

Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur

Faculty Publications, Chemistry

Type II restriction enzymes are homodimeric systems that bind four to eight base pair palindromic recognition sequences of DNA and catalyze metal ion-dependent phosphodiester cleavage. While Mg(II) is required for cleavage in these enzymes, in some systems Ca(II) promotes avid substrate binding and sequence discrimination. These properties make them useful model systems for understanding the roles of alkaline earth metal ions in nucleic acid processing. We have previously shown that two Ca(II) ions stimulate DNA binding by PvuII endonuclease and that the trivalent lanthanide ions Tb(III) and Eu(III) support subnanomolar DNA binding in this system. Here we capitalize on this …

Theory And Experiments: Scf Calculations/Xrd/Enhanced Scattering/Pld In Ybco7-D Nano Film, H. Sahibudeen, M. Navacerrada, Juana Acrivos

Faculty Publications, Chemistry

X-Ray diffraction above and below the transition temperature to superconductivity Tc are correlated using SCF-MOLECOLE computations that describe the CuO2 layer (fig. 1) in the field of 9 unit cells of YBa2Cu3O7. The MO symmetry, charge transfer and OAOB bond mobility are compared to the data using the highest occupiedmolecular orbitals, MO-i (HOMO=MO0) bases to construct the layer tight-binding extended state.

"A New Phase Of The Complex Trinitratotris(Triphenylphosphineoxide)Neodymium(Lll), J. Brannon Gary

Faculty Publications

There has been considerable interest in the complexes formed by the lanthanides with various monodentate neutral ligands with O as the donor atom. Phosphine oxides, in particular, have proven useful in complexing to lanthanide metal ions and have found practical application in the solvent extraction and separation of lanthanides.1 Several lanthanide(III) nitrate complexes with triphenylphosphine oxide (OPPh3) have been prepared resulting in complexes having as few as two and as many as four OPPh3 groups per lanthanide center.2−4 An earlier study by Cousins and Hart5 identified the complex [Nd(OPPh3)3(NO3)3]. Two crystal phases of this same complex were briefly reported later …

2,2':6',2"-Terpyridine N,N',N"-Trioxide, Kraig A. Wheeler, Scott E. Mckay, Silas C. Blackstock

Faculty Research and Creative Activity

No abstract provided.

Comparing Models For Measuring Ring Strain Of Common Cycloalkanes, Brad A. Hobbs

The Corinthian

The number of carbon atoms bonded in the ring of a cycloalkane has a large effect on its energy. A molecule's energy has a vast impact on its stability. Determining the most stable form of a molecule is a useful technique in the world of chemistry. One of the major factors that influence the energy (stability) of cycloalkanes is the molecule's ring strain. Ring strain is normally viewed as being directly proportional to the instability of a molecule. It is defined as a type of potential energy within the cyclic molecule, and is determined by the level of "strain" between …

The Effects Of Multiple Mutations In The Hydrophobic Core Upon The Stability Of Staphylococcal Nuclease, Rebecca L. Danforth

Inquiry: The University of Arkansas Undergraduate Research Journal

Previous work in the laboratory of my research advisor, Dr. Wesley Stites, has investigated the core packing of the protein staphylococcal nuclease. The core of a protein is critical in determining a protein's structure and stability. The hydrophobicity of the core has long been thought to be the principal driving force for folding, but recent work in the Stites lab has shown that optimization of van der Waals contacts and minimization of cavities, in our shorthand term, packing, is at least as energetically important. We are building upon this information in our attempt to better pack the protein core. If …

Development Of An Analytical Method For Distinguishing Ammonium Bicarbonate From The Products Of An Aqueous Ammonia Co2 Scrubber And The Characterization Of Ammonium Bicarbonate, Lingyu Meng

Masters Theses & Specialist Projects

The link between anthropogenic emissions of CO2 with increased atmospheric CO2 levels and, in turn, with increased global temperature has been well established and accepted. Using aqueous ammonia to capture CO2 and produce an inexpensive nitrogen fertilizer, ammonium bicarbonate (ABC) has been thought as a feasible approach to CO2 sequestration.

Due to the different concentrations of reactants and reaction conditions, different carbon-ammonium composites can be produced. In view of achieving a maximum of NH3 utilization in the capture of CO2, the product of ABC will be ideal. Hence the ABC in the products needs to be identified. Various analytical techniques …

Reduced Acetylcholine Receptor Density, Morphological Remodeling, And Butyrylcholinesterase Activity Can Sustain Muscle Function In Acetylcholinesterase Knockout Mice, Michael Adler, Heather A. Manley, Angela L. Purcell, Sharad S. Deshpande, Tracey A. Hamilton, Robert K. Kan, George Oyler, Oksana Lockridge, Ellen G. Duysen, Robert E. Sheridan

United States Army: Publications

The vertebrate neuromuscular junction is designed for rapid transmission of excitatory signals for initiation of muscle contraction.5 Among the features responsible for the high throughput of this synapse are the close proximity of the presynaptic and postsynaptic membranes,10 the direct coupling of acetylcholine (ACh) binding to the opening of the ion channel associated with the nicotinic acetylcholine receptor (nAChR),27 the brief open time of this channel,21,27 and the presence of cholinesterase (ChE) for hydrolysis of ACh.21,30 At the endplate, there are two distinct ChEs for transmitter hydrolysis: acetylcholinesterase (EC 3.1.1.7, AChE) and butyrylcholinesterase (EC 3.1.1.8, BChE).33 Both enzymes can …

Accuracy And Interferences For Enzyme-Linked Immunoassay Tests For Atrazine, Craig D. Adams, Hua Jiang, Michael Mcguire, Nicole Graziano, Alan Roberson, Michelle Frey

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Atrazine is one of the most commonly used herbicides in the United States, therefore it is a regulatory concern and is extensively monitored in the environment, especially in drinking water. Because of the higher costs of gas chromatography (GC) methods, utility managers and regulators are considering the increased use of enzyme-linked immunosorbent assay (ELISA) methods for monitoring atrazine. an ELISA test kit was recently approved by the US Environmental Protection Agency. the research in this article points out potential biases and inaccuracies that may occur with such test kits. ELISA test kits for atrazine are typically precise (repeatable) but often …

New Organic/Inorganic Hybrid Sol-Gel Nanocomposite Materials For Raman Gain In Fiber Optics, Stephen James Andrasik

Electronic Theses and Dissertations

The recent increased availability of additional wavelengths in the telecommunications window of about 1300-1600 nm has generated an interest in new optical materials and devices that can operate outside the normally used regions of 840 nm, 1310 nm, and 1550 nm. Specifically, methods to amplify fiber optical data transmission in the regions where there is limited or no existing methods to achieve amplification is of interest in the chemistry and photonic communities. Raman gain is one method that has been proposed to passively amplify optical data transmission through a distributed process. Amplification is obtained through a nonlinear light scattering process …

Gated Electron Transfer As A Probe Of The Configurational Dynamics Of Peptide−Protein Complexes, Liu Liu, Jing Hong, Michael Y. Ogawa

Chemistry Faculty Publications

Gated electron-transfer measurements are used to probe the configurational dynamics of complexes formed between small metallopeptides and cytochrome c. The results show that that an apparently subtle chemical alteration of the metallopeptide produces significant changes to the dynamics of the peptide−protein complex.

An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül

Turkish Journal of Chemistry

2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …

Cationic Rearrangements Of An Endo}-Cyclopropyl Methanol System Incorporated In A Benzonorbornadiene System, Abdullah Menzek, Melek Karakaya

Turkish Journal of Chemistry

Chloride 18 (47%) and alcohol 21 (44%) were isolated from the reaction of alcohol 20 with SOCl_2. Cyclopropylcarbinyl -- cyclopropylcarbinyl rearrangement leads to chloride 22, which hydrolyses on separation to give alcohol 21. Chloride 18 results from cyclopropyl -- allylcarbinyl rearrangement, followed by a 1,2 -- aryl shift (sequential rearrangement). Syntheses of compounds 23 and 24 support the structures. The behaviour of 20 differs from that of exo isomer 14, probably due to the nature of the intermediates in these reactions.

Facile Synthesis Of Hydantoin Derivatives Under Microwave Irradiation, Khalil Faghihi, Khosrow Zamani, Akbar Mobinikhaledi

Turkish Journal of Chemistry

The rapid and highly efficient synthesis of hydantoin derivatives 3(a-f) was achieved under microwave irradiation by using a domestic microwave oven from the reactions of cyanohydrin derivatives 2(a-f) with ammonium carbonate. The reaction proceeded rapidly (2-5 min.), and as a result a series of hydantoin derivatives 3(a-f) were obtained in high yields. All of the synthesized compounds were fully characterized by their melting point, ^1H-NMR, FTIR spectroscopy and elemental analyses. Cyanohydrin derivatives 2(a-f) were also prepared from the ketone derivatives 1(a-f) with potassium cyanide in the presence of sodium metabisulfite in an additional reaction.

Anionic Polymerization Of Methyl Methacrylate As Promoted By A N-Butyl Lithium-Pyridazine-Polyether Alkoxide Based Complex Initiator System, Z. Tim Hamaudi, Ni̇han Nugay, Turgut Nugay

Turkish Journal of Chemistry

Polymerization of methyl methacrylate was conducted using a n-butyl lithium/pyridazine system as initiator in tetrahydrofuran (THF) and toluene. Special attention was focused on using some lithium polyether alkoxides as polymerization is promoted at ambient temperatures. The positive effects of these \mu /\sigma -type ligands such as lithium 2-(2-methoxyethoxy)ethoxide and lithium 2-(methoxy)ethoxide on controlling the living character, molecular weight, stereoregularity and yield of the produced polymers were all demonstrated. It was found that initiator/lithium-2-(methoxy)ethoxide in a 1/10 ratio gives the most controlled polymerization. All products were then characterized by size exclusion chromatography (SEC), proton nuclear magnetic resonance (^1H NMR) and differential …

Part I: Evaluation Of Russian Synthetic Compounds As A Potential Source Of New Drug Leads Agains Breast And Colon Cancer Part Ii: Isolation Of Beta-Amyrin Formate From Eucalyptus Viminalis Labill And Investigation Of Its Colon Cancer Activity, Mihaela Cohanoschi

Electronic Theses and Dissertations

Although modern medicine made great steps toward curing most diseases considered deadliest, yet cancer remains one of the major public health problems. The first part of this thesis investigates a new source of selective compounds that are potential candidates against cancer. Fifteen Russian compounds were tested in order to establish their efficiency against two types of cancer: human breast SK-Br-3 and colorectal carcinoma HT-29. The bioassay results show that seven of the new synthetic Russian compounds can be considered new drug leads, based upon their low toxicity and efficacy in slowing the growth of human breast cancer and colon cancer …

Application Of Pyrolysis-Gc/Ms For Rapid Assessment Of Organic Contamination In Sediments From Barcelona Harbor, Michael A. Kruge, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Pyrolysis-GC/MS is advantageous as a tool for rapid sediment contamination assessment because of the small sample size required, minimal sample preparation, and its ability to detect a wide variety of organic pollutants as well as naturally-occurring biological materials. Py-GC/MS was applied, together with determination of organic carbon, and major and minor element concentrations, to evaluate potentially contaminated sediments in the port of Barcelona (Spain) and the adjacent Llobregat River delta. Detected contaminant markers, most evident in the Old Port (Port Vell) area, included hopanes and alkylated PAHs (petroleum), sterenes (sewage), C₁₆-C₁₉ phenylalkanes (detergents) and parent …

Solvent-Free Conversion Of Alpha-Naphthaldehyde To 1-Naphthoic Acid And 1-Naphthalenemethanol: Application Of The Cannizzaro Reaction, John J. Esteb, Keith M. Glogorich, Stacey A. O'Reilly

Scholarship and Professional Work - LAS

The Cannizzaro reaction is routinely covered in organic textbooks, but owing to the shortage of suitable procedures for the undergraduate teaching laboratory, this reaction is seldom performed in a first-year organic chemistry class. In this experiment, powdered potassium hydroxide and α-naphthaldehyde are heated under solvent-free conditions to produce 1-naphthoic acid and 1-naphthalenemethanol in 86% and 79% yields, respectively. The solvent-free nature of this procedure greatly reduces the quantity of waste generated by students relative to the typical solvent-based method of preparation. Note:Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information …

Simple Epoxide Formation For The Organic Laboratory Using Oxone, John J. Esteb

Scholarship and Professional Work - LAS

We present an epoxide formation experiment for a second-semester organic chemistry laboratory. This oxidation utilizes Oxone, a commercially available oxidizing agent, in the industrially relevant process of epoxide formation. The oxidant performing the oxidation is dimethyldioxirane, which is formed in situ. This experiment demonstrates a simple synthesis of an epoxide and formation of a secondary oxidizing agent.

Cautionary Comments (Author Response), John J. Esteb, Anne M. Wilson

Scholarship and Professional Work - LAS

Reply to concerns about a safety factor in the paper, “A Solvent-Free Oxidation of Alcohols in an Organic Laboratory."

Synthesis, Characterization Of Some Co(Iii) Complexes With Vic-Dioxime Ligands And Their Antimicrobial Properties, Erdal Canpolat, Mehmet Kaya, Seher Gür

Turkish Journal of Chemistry

In this study, 6 different new vic-dioxime ligands and their mononuclear complexes with Co(III) have been synthesized. The structures of these compounds were identified by using elemental analyses, IR, ^{1}H and ^{13}C NMR, electronic spectra, magnetic susceptibility measurements and conductivity. In addition, the thermal characterizations and antimicrobial activities of the ligands and their complexes have been investigated.

An Efficient Synthesis Of Substituted 4-Aryl-3-Cyano-2-Amino Thiophenes By A Stepwise Gewald Reaction, Ferhan Tümer, Duygu Eki̇nci̇, Kani̇ Zi̇lbeyaz, Ümi̇t Demi̇r

Turkish Journal of Chemistry

The title compounds were efficiently synthesised starting from aryl methyl ketones in 3 steps. Knoevenagel condensation of aryl methyl ketones with malononitrile gave the corresponding crotonitriles (5a-f). Methyl groups of the crotonitriles (5a-f) were then efficiently brominated by refluxing and lightening the reaction media to give bromocrotonitriles (6a-f). The bromocrotonitriles (6a-f) were finally cyclised by treatment with NaSH to give the title compounds.

Analysis Of Free Analyte Fractions By Rapid Affinity Chromatography, David S. Hage, William A. Clarke

Department of Chemistry: Faculty Publications

The invention is generally directed toward an analytical method to determine the concentration of the free analyte fraction in a sample. More particularly, the method encompasses applying a sample comprising a free and bound analyte fraction to an affinity column capable of selectively extracting the free fraction in the millisecond time domain. The signal generated by the free fraction is then quantified by standard analytical detection techniques. The concentration of the free fraction may then be determined by comparison of its signal with that of a calibration curve depicting the signal of known concentration of the same analyte.

Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be …

Iron-Promoted Remediation Of Atrazine: Solution And Amended Sandy Column Studies, Donghua Zeng

Masters Theses

No abstract provided.