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Chemistry Faculty Publications

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Articles 481 - 510 of 1129

Full-Text Articles in Chemistry

Designing Conical Intersections For Light-Driven Single Molecule Rotary Motors: From Precessional To Axial Motion, Michael Filatov, Massimo Olivucci Apr 2014

Designing Conical Intersections For Light-Driven Single Molecule Rotary Motors: From Precessional To Axial Motion, Michael Filatov, Massimo Olivucci

Chemistry Faculty Publications

In the past, the design of light-driven single molecule rotary motors has been mainly guided by the modification of their ground-state conformational properties. Further progress in this field is thus likely to be achieved through a detailed understanding of light-induced dynamics of the system and the ways of modulating it by introducing chemical modifications. In the present theoretical work, the analysis of model organic chromophores and synthesized rotary motors is used for rationalizing the effect of electron-withdrawing heteroatoms (such as a cationic nitrogen) on the topography and branching plane of mechanistically relevant conical intersections. Such an analysis reveals how the …


Lead Optimization Of Hmba To Develop Potent Hexim1 Inducers, Bo Zhong, Rati Lama, Wannarasmi Ketchart, Monica M. Montano, Bin Su Mar 2014

Lead Optimization Of Hmba To Develop Potent Hexim1 Inducers, Bo Zhong, Rati Lama, Wannarasmi Ketchart, Monica M. Montano, Bin Su

Chemistry Faculty Publications

The potency of a series of Hexamethylene bis-acetamide (HMBA) derivatives inducing Hexamethylene bis-acetamide inducible protein 1 (HEXIM1) was determined in LNCaP prostate cancer cells. Several compounds with unsymmetrical structures showed significantly improved activity. Distinct from HMBA, these analogs have increased hydrophobicity and can improve the short half-life of HMBA, which is one of the factors that have limited the application of HMBA in clinics. The unsymmetrical scaffolds of the new analogs provide the basis for further lead optimization of the compounds using combinatorial chemistry strategy.


Drug Analogs Of Cox-2 Selective Inhibitors Lumiracoxib And Valdecoxib Derived From In Silico Search And Optimization, Ronald Bartzatt Mar 2014

Drug Analogs Of Cox-2 Selective Inhibitors Lumiracoxib And Valdecoxib Derived From In Silico Search And Optimization, Ronald Bartzatt

Chemistry Faculty Publications

The medicinal activity of COX-2 inhibitors are sufficiently beneficial to urge the search for new drug designs. This study presents 16 analogs of lumiracoxib and 10 analogs to valdecoxib having properties suitable as COX-2 inhibitors. For lumiracoxib analogs the mean Log P, polar surface area, and formula weight are 3.00, 70.46 A2, and 276.60, respectively. For valdecoxib analogs the mean Log P, polar surface area, and formula weight are 3.65, 68.46 A2, and 322.32, respectively. Grubb’s test analysis of seven properties for seven known COX-2 selective inhibitors and those of 26 analog compounds indicated no outliers. The unpaired t-test compared …


Selective Anion Sensing By Chiral Macrocyclic Receptors With Multiple Hydrogen-Bonding Sites, Tadashi Ema, Keiichi Okuda, Sagiri Watanabe, Takayuki Yamasaki, Tsuyoshi Minami, Nina A. Esipenko, Pavel Anzenbacher Jr. Mar 2014

Selective Anion Sensing By Chiral Macrocyclic Receptors With Multiple Hydrogen-Bonding Sites, Tadashi Ema, Keiichi Okuda, Sagiri Watanabe, Takayuki Yamasaki, Tsuyoshi Minami, Nina A. Esipenko, Pavel Anzenbacher Jr.

Chemistry Faculty Publications

Chiral macrocycles featuring sulfonamide and/or amide groups as anion-binding sites were synthesized. X-ray crystal structures and DFT calculations have shown that they adopt different conformations that may lead to unique binding behavior. Indeed, various anions could be sensed by their colorimetric and/or fluorescence signal output. The chiral macrocycles showed chiral recognition for chiral anions. Furthermore, a multisensor array with two or four chiral receptors discriminated seven phosphate anions (AMP, ADP, ATP, CMP, GMP, Pi, and PPi) with 100% classification accuracy.


Multi-Technique Quantitative Analysis And Socioeconomic Considerations Of Lead, Cadmium, And Arsenic In Children's Toys And Toy Jewelry, Margot M. Hillyer, Lauren E. Finch, Alisha S. Cerel, Jonathan D. Dattelbaum, Michael C. Leopold Feb 2014

Multi-Technique Quantitative Analysis And Socioeconomic Considerations Of Lead, Cadmium, And Arsenic In Children's Toys And Toy Jewelry, Margot M. Hillyer, Lauren E. Finch, Alisha S. Cerel, Jonathan D. Dattelbaum, Michael C. Leopold

Chemistry Faculty Publications

A wide spectrum and large number of children’s toys and toy jewelry items were purchased from both bargain and retail vendors and analyzed for arsenic, cadmium, and lead metal content using multiple analytical techniques, including flame and furnace atomic absorption spectroscopy as well as X-ray fluorescence spectroscopy. Particularly dangerous for young children, metal concentrations in toys/toy jewelry were assessed for compliance with current Consumer Safety Product Commission (CPSC) regulations (F963-11). A conservative metric involving multiple analytical techniques was used to categorize compliance: one technique confirmation of metal in excess of CPSC limits indicated a “suspect” item while confirmation on two …


Functional Relevance Of Acrb Trimerization In Pump Assembly And Substrate Binding, Wei Lu, Meng Zhong, Qian Chai, Zhaoshuai Wang, Linliang Yu, Yinan Wei Feb 2014

Functional Relevance Of Acrb Trimerization In Pump Assembly And Substrate Binding, Wei Lu, Meng Zhong, Qian Chai, Zhaoshuai Wang, Linliang Yu, Yinan Wei

Chemistry Faculty Publications

AcrB is a multidrug transporter in the inner membrane of Escherichia coli. It is an obligate homotrimer and forms a tripartite efflux complex with AcrA and TolC. AcrB is the engine of the efflux machinery and determines substrate specificity. Active efflux depends on several functional features including proton translocation across the inner membrane through a proton relay pathway in the transmembrane domain of AcrB; substrate binding and migration through the substrate translocation pathway; the interaction of AcrB with AcrA and TolC; and the formation of AcrB homotrimer. Here we investigated two aspects of the inter-correlation between these functional features, …


A Review Of Air–Ice Chemical And Physical Interactions (Aici): Liquids, Quasi-Liquids, And Solids In Snow, T. Bartels-Rausch, H. -W. Jacobi, T. F. Kahan, J. L. Thomas, E. S. Thomson, J. P. D. Abbatt, M. Ammann, J. R. Blackford, H. Bluhm, C. Boxe, F. Domine, M. M. Frey, I. Gladich, M. I. Guzmán, D. Heger, Th. Huthwelker, P. Klán, W. F. Kuhs, M. H. Kuo, S. Maus, S. G. Moussa, V. F. Mcneill, J. T. Newberg, J. B. C. Pettersson, M. Roeselová, J. R. Sodeau Feb 2014

A Review Of Air–Ice Chemical And Physical Interactions (Aici): Liquids, Quasi-Liquids, And Solids In Snow, T. Bartels-Rausch, H. -W. Jacobi, T. F. Kahan, J. L. Thomas, E. S. Thomson, J. P. D. Abbatt, M. Ammann, J. R. Blackford, H. Bluhm, C. Boxe, F. Domine, M. M. Frey, I. Gladich, M. I. Guzmán, D. Heger, Th. Huthwelker, P. Klán, W. F. Kuhs, M. H. Kuo, S. Maus, S. G. Moussa, V. F. Mcneill, J. T. Newberg, J. B. C. Pettersson, M. Roeselová, J. R. Sodeau

Chemistry Faculty Publications

Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to summarise the current state of knowledge of physical processes and chemical reactivity in surface snow with relevance to polar regions. It focuses on a description of impurities in distinct compartments present in surface snow, such as snow crystals, grain boundaries, crystal surfaces, and liquid parts. It emphasises the microscopic description of the ice surface and its link with the environment. Distinct differences between the disordered air–ice interface, often termed quasi-liquid …


An Abundant Dysfunctional Apolipoprotein A1 In Human Atheroma, Ying Huang, Joseph A. Didonato, Bruce S. Levison, Dave Schmitt, Lin Li, Yuping Wu, Jennifer Buffa, Timothy Kim, Gary S. Gerstenecker, Xiaodong Gu, Chandra S. Kadiyala, Zeneng Wang, Miranda K. Culley, Jennie E. Hazen, Anthony J. Didonato, Xiaoming Fu, Stela Z. Berisha, Daoquan Peng, Truc T. Nguyen, Shaohong Liang, Chia-Chi Chuang, Leslie Cho, Edward F. Plow, Paul L. Fox, Valentin Gogonea, W.H. Wilson Tang, John S. Parks, Edward A. Fisher, Jonathan D. Smith, Stanley L. Hazen Feb 2014

An Abundant Dysfunctional Apolipoprotein A1 In Human Atheroma, Ying Huang, Joseph A. Didonato, Bruce S. Levison, Dave Schmitt, Lin Li, Yuping Wu, Jennifer Buffa, Timothy Kim, Gary S. Gerstenecker, Xiaodong Gu, Chandra S. Kadiyala, Zeneng Wang, Miranda K. Culley, Jennie E. Hazen, Anthony J. Didonato, Xiaoming Fu, Stela Z. Berisha, Daoquan Peng, Truc T. Nguyen, Shaohong Liang, Chia-Chi Chuang, Leslie Cho, Edward F. Plow, Paul L. Fox, Valentin Gogonea, W.H. Wilson Tang, John S. Parks, Edward A. Fisher, Jonathan D. Smith, Stanley L. Hazen

Chemistry Faculty Publications

Recent studies have indicated that high-density lipoproteins (HDLs) and their major structural protein, apolipoprotein A1 (apoA1), recovered from human atheroma are dysfunctional and are extensively oxidized by myeloperoxidase (MPO). In vitro oxidation of either apoA1 or HDL particles by MPO impairs their cholesterol acceptor function. Here, using phage display affinity maturation, we developed a high-affinity monoclonal antibody that specifically recognizes both apoA1 and HDL that have been modified by the MPO-H2O2-Cl− system. An oxindolyl alanine (2-OH-Trp) moiety at Trp72 of apoA1 is the immunogenic epitope. Mutagenesis studies confirmed a critical role for apoA1 Trp72 in MPO-mediated inhibition of the ATP-binding …


Detection And Assay Of Riboflavin (Vitamin B2) Utilizing Uv/Vis Spectrophotometer And Citric Acid Buffer, Ronald Bartzatt, Michelle Lee Follis Jan 2014

Detection And Assay Of Riboflavin (Vitamin B2) Utilizing Uv/Vis Spectrophotometer And Citric Acid Buffer, Ronald Bartzatt, Michelle Lee Follis

Chemistry Faculty Publications

Aims: Riboflavin is a B vitamin that is required for a wide variety of cellular processes. The absorbance spectrum of riboflavin was determined at different pH utilizing several buffers. The buffer at pH demonstrating table absorbance peaks with high numerical values of molar absorptivity is followed by accurate and sensitive assay of riboflavin by spectrophotometer. Study Design: The absorbance spectrum of riboflavin is determined in an aqueous buffer at various pH values. After identifying the absorbance peaks providing maximal molar absorptivity the assay of riboflavin in the identical buffer was undertaken. Place and Duration of Study: Department of Chemistry, Durham …


Bsa–Boronic Acid Conjugate As Lectin Mimetics, Satya Nandana Narla, Poornima Pinnamaneni, Huan Nie, Yu Li, Xue-Long Sun Jan 2014

Bsa–Boronic Acid Conjugate As Lectin Mimetics, Satya Nandana Narla, Poornima Pinnamaneni, Huan Nie, Yu Li, Xue-Long Sun

Chemistry Faculty Publications

We report bovine serum albumin (BSA)–boronic acid (BA) conjugates as lectin mimetics and their glyco-capturing capacity. The BSA–BA conjugates were synthesized by amidation of carboxylic acid groups in BSA with aminophenyl boronic acid in the presence of EDC, and were characterized by Alizarin Red S (ARS) assay and SDS–PAGE gel. The BSA–BA conjugates were immobilized onto maleimide-functionalized silica beads and their sugar capturing capacity and specificity were confirmed by ARS displacement assay. Further, surface plasmon resonance (SPR) analysis of the glyco-capturing activity of the BSA–BA conjugates was conducted by immobilizing BSA–BA onto SPR gold chip. Overall, we demonstrated a BSA–BA-based …


Effects Of Oxidation On Protein-Nanoparticle Interactions, Valdez R. Rahming, Md. Abul Fazal Jan 2014

Effects Of Oxidation On Protein-Nanoparticle Interactions, Valdez R. Rahming, Md. Abul Fazal

Chemistry Faculty Publications

Aims: Upon entrance into the blood stream most nanoparticles bind to an array of proteins forming a “protein corona”. Fibrinogen is the second most abundant blood protein and has been reported to bind to a variety of nanoparticles including metal oxides, polymeric nanoparticles and carbon nanotubes.
Study Design: Study the effects of oxidation on the binding interactions between human serum fibrinogen and magnetic iron (III) oxide nanoparticles.
Place and Duration of Study: Department of Chemistry, College of St. Benedict, 37 South College Avenue, St. Joseph, MN 56374, U.S.A., between June 2011 and May 2012.
Methodology: Spectroscopic techniques (UV-Vis, IR, fluorescence, …


Enhanced Lifetime Of Excitons In Nonepitaxial Au/Cds Core/Shell Nanocrystals, Scott Lambright, Evgeniia Butaeva, Natalia Razgoniaeva, Thomas Hopkins, Bryan Smith, Dimuthu Perera, Jonathan Corbin, Elena Khon, Rebekah Thomas, Pavel Moroz, Andrey Mereshchenko, Alexander N. Tarnovsky, Mikhail Zamkov Jan 2014

Enhanced Lifetime Of Excitons In Nonepitaxial Au/Cds Core/Shell Nanocrystals, Scott Lambright, Evgeniia Butaeva, Natalia Razgoniaeva, Thomas Hopkins, Bryan Smith, Dimuthu Perera, Jonathan Corbin, Elena Khon, Rebekah Thomas, Pavel Moroz, Andrey Mereshchenko, Alexander N. Tarnovsky, Mikhail Zamkov

Chemistry Faculty Publications

The ability of metal nanoparticles to capture light through plasmon excitations offers an opportunity for enhancing the optical absorption of plasmon-coupled semiconductor materials via energy transfer. This process, however, requires that the semiconductor component is electrically insulated to prevent a "backward" charge flow into metal and interfacial states, which causes a premature dissociation of excitons. Here we demonstrate that such an energy exchange can be achieved on the nanoscale by using nonepitaxial Au/CdS core/shell nanocomposites. These materials are fabricated via a multistep cation exchange reaction, which decouples metal and semiconductor phases leading to fewer interfacial defects. Ultrafast transient absorption measurements …


Synthesis And Evaluation Of Some New Aza-B-Homocholestane Derivatives As Anticancer Agents, Yanmin Huang, Jianguo Cui, Sijing Chen, Qifu Lin, Huacan Song, Chunfang Gan, Bin Su, Aimin Zhou Jan 2014

Synthesis And Evaluation Of Some New Aza-B-Homocholestane Derivatives As Anticancer Agents, Yanmin Huang, Jianguo Cui, Sijing Chen, Qifu Lin, Huacan Song, Chunfang Gan, Bin Su, Aimin Zhou

Chemistry Faculty Publications

Using analogues of some marine steroidal oximes as precursors, a series of aza-B-homocholestane derivatives possessing different substituted groups at the 3-position of the steroidal nucleus were synthesized. Their biological activity against cancer cell proliferation was determined with multiple cancer cell lines. Aza-B-homocholestane derivatives possessing 3-hydroxyl, 3-hydroximino and 3-thiosemicarbazone groups displayed remarkable cytotoxicity to cancer cells via apoptosis inducing mechanism. Compounds 5, 10, 12, 15 and 18 exhibited better potency to inhibit cancer cell proliferation. In addition, compound 15 was further evaluated with three dimensional (3D) multicellular spheroids assay to determine its potency against spheroid growth. The structure-activity relationship (SAR) generated …


Nonexistent Compounds As A Guide To Innovation, Dean F. Martin, Barbara B. Martin Jan 2014

Nonexistent Compounds As A Guide To Innovation, Dean F. Martin, Barbara B. Martin

Chemistry Faculty Publications

A study of nonexistent compounds can be a useful exercise in gaining insight into the factors that can inhibit innovation. Several reasons are suggested: lack of financial support, disinterest in preparing compounds that lack evident utility, notable synthetic challenges with inadequate rewards, inhibition by well-established contemporary knowledge, and invalid interpolations.


Polyaniline In Situ Grafted To Graphene Sheets, Erwin P. Enriquez, Elliard Roswell S. Yanza, Geoffrey Matthew C. Tan, Christine Joy Querebilo, Armando Somintac, Arnel Salvador Jan 2014

Polyaniline In Situ Grafted To Graphene Sheets, Erwin P. Enriquez, Elliard Roswell S. Yanza, Geoffrey Matthew C. Tan, Christine Joy Querebilo, Armando Somintac, Arnel Salvador

Chemistry Faculty Publications

Graphene is one of the most promising allotropes of carbon with wide applications in nanotechnology. Modification of graphene by chemical means can further expand its uses. Here, liquid-exfoliated graphene is functionalized with p-aminophenyl moiety using p-nitrophenyl diazonium salts which were diazotized in situ then reduced by tin(II) chloride. The aminophenyl-graphene thus produced is further modified to form polyaniline-graphene (PANI-GNH) by in situ oxidative graft polymerization of aniline using ammonium peroxydisulfate as oxidizing agent. The properties of the PANI-GNH were compared with polyaniline/graphene blends by Raman, infrared and UV-Visible spectroscopy, and cyclic voltammetry. Indeed, PANI-GNH registered different spectrochemical and electrochemical properties …


Quantification Of Free Sialic Acid In Human Plasma Through A Robust Quinoxalinone Derivatization And Lc–Ms/Ms Using Isotope-Labeled Standard Calibration, Dan Wang, Xiang Zhou, Lin Wang, Sihe Wang, Xue-Long Sun Jan 2014

Quantification Of Free Sialic Acid In Human Plasma Through A Robust Quinoxalinone Derivatization And Lc–Ms/Ms Using Isotope-Labeled Standard Calibration, Dan Wang, Xiang Zhou, Lin Wang, Sihe Wang, Xue-Long Sun

Chemistry Faculty Publications

We report an accurate quantification of free sialic acid (SA) in human plasma using LC–MS/MS method with isotope-labeled standard calibration (ILSC) and robust derivatization. Specifically, derivatization of SA with a stable and inexpensive 3,4-diaminotoluene (DAT) provides a stable product of SA with high MS response, proving a convenient and cost-effective LC–MS/MS analysis of free SA. In addition, the use of 13C3-SA as calibration standard ensured the accuracy for the measurement. This assay used ultra high performance liquid chromatography (UHPLC) for separation of native/labeled SA and IS from matrix interference, and employed mass spectrometry in multiple reaction monitoring …


Glyco-Modification Of Protein With O-Cyanate Chain-End Functionalized Glycopolymer Via Isourea Bond Formation, Valentinas Gruzdys, Hailong Zhang, Xue-Long Sun Jan 2014

Glyco-Modification Of Protein With O-Cyanate Chain-End Functionalized Glycopolymer Via Isourea Bond Formation, Valentinas Gruzdys, Hailong Zhang, Xue-Long Sun

Chemistry Faculty Publications

Glycoengineering aimed at addition of carbohydrates to proteins is an attractive approach to alter pharmacokinetic properties of proteins such as enhancing stability and prolonging the duration of action. We report a novel protein glyco-modification of BSA and recombinant thrombomodulin with O-cyanate chain-end functionalized glycopolymer via isourea bond formation. The protein glycoconjugates were confirmed by SDS-PAGE, western blot, and MALDI-TOF Mass Spectrometry. Protein C activation activity of the glyco-modified recombinant thrombomodulin was confirmed, proving no interference to activity from the glycopolymer modification. The isourea bond formation under mild conditions was demonstrated as an alternative method for protein modification with polymers.


The Mechanism Of Galvanic/Metal-Assisted Etching Of Silicon, Kurt W. Kolasinski Jan 2014

The Mechanism Of Galvanic/Metal-Assisted Etching Of Silicon, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.


Bubbles: A Review Of Their Relationship To The Formation Of Thin Films And Porous Materials, Kurt W. Kolasinski Jan 2014

Bubbles: A Review Of Their Relationship To The Formation Of Thin Films And Porous Materials, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.


A Kinetic Analysis Of The Inhibition Of Fox-4 Β-Lactamase, A Plasmid-Mediated Ampc Cephalosporinase, By Monocyclic Β-Lactams And Carbapenems, Krisztina M. Papp-Wallace, Susana Mallo, Christopher R. Bethel, Magdalena A. Taracila, Andrea M. Hujer, Ana Fernandez, Julian A. Gatta, Kerri M. Smith, Yan Xu, Malcolm G.P. Page, Eric Desarbre, German Bou, Robert A. Bonomo Jan 2014

A Kinetic Analysis Of The Inhibition Of Fox-4 Β-Lactamase, A Plasmid-Mediated Ampc Cephalosporinase, By Monocyclic Β-Lactams And Carbapenems, Krisztina M. Papp-Wallace, Susana Mallo, Christopher R. Bethel, Magdalena A. Taracila, Andrea M. Hujer, Ana Fernandez, Julian A. Gatta, Kerri M. Smith, Yan Xu, Malcolm G.P. Page, Eric Desarbre, German Bou, Robert A. Bonomo

Chemistry Faculty Publications

Abstract: Objectives: Class C β-lactamases are prevalent among Enterobacteriaceae; however, these enzymes are resistant to inactivation by commercially available β-lactamase inhibitors. In order to find novel scaffolds to inhibit class C β-lactamases, the comparative efficacy of monocyclic β-lactam antibiotics (aztreonam and the siderophore monosulfactam BAL30072), the bridged monobactam β-lactamase inhibitor BAL29880, and carbapenems (imipenem, meropenem, doripenem and ertapenem) were tested in kinetic assays against FOX-4, a plasmid-mediated class C β-lactamase (pmAmpC). Methods: The FOX-4 β-lactamase was purified. Steady-state kinetics, electrospray ionization mass spectrometry (ESI-MS) and ultraviolet difference (UVD) spectroscopy were conducted using the β-lactam scaffolds described. Results: The Ki values …


Novel Tuberculostatic Agents Suitable For Treatment Of Mycobacterium Tuberculosis Infections Of The Central Nervous System, Ronald Bartzatt, Preeti Sule, Suat L.G. Cirillo, Jeffrey D. Cirillo Jan 2014

Novel Tuberculostatic Agents Suitable For Treatment Of Mycobacterium Tuberculosis Infections Of The Central Nervous System, Ronald Bartzatt, Preeti Sule, Suat L.G. Cirillo, Jeffrey D. Cirillo

Chemistry Faculty Publications

Aims: To demonstrate the efficacy of five small molecule compounds for inhibiting the growth of Mycobacterium tuberculosis. To present evidence that these compounds will penetrate into the central nervous system.

Study Design: Five small molecule compounds bearing a hydrazide group were synthesized utilizing microwave excitation. These compounds were then placed into tissue culture with Mycobacterium tuberculosis at various concentrations for evaluation of bacterial growth inhibition.

Place and Duration of Study: The compounds to be tested were prepared at the University of Nebraska Chemistry Department August 2013. The evaluation of antibacterial activity was determined at the Texas A&M Health Science …


Science Classics, Mark Masthay Jan 2014

Science Classics, Mark Masthay

Chemistry Faculty Publications

An essay on the impact of the works in the Imprints and Impressions: Milestones in Human Progress, an exhibition of rare books from the collection of Stuart Rose. Exhibition was held Sept. 29-Nov. 9, 2014, at the University of Dayton.


Electronic Effects In Oxidation Reactions Utilizing Dinuclear Copper Complexes With The Bis[3-(2-Hydroxybenzylideneamino)Phenyl] Sulfone Ligand, Armando M. Guidote Jr, Ronald L. Reyes, Riyo Kashihara, Yasuhiko Kurusu, Yoshihiro Masuyama Jan 2014

Electronic Effects In Oxidation Reactions Utilizing Dinuclear Copper Complexes With The Bis[3-(2-Hydroxybenzylideneamino)Phenyl] Sulfone Ligand, Armando M. Guidote Jr, Ronald L. Reyes, Riyo Kashihara, Yasuhiko Kurusu, Yoshihiro Masuyama

Chemistry Faculty Publications

Copper acetate and the ligands bis[3-(3-tert-butyl-2-hydroxy-5-methoxybenzylideneamino)phenyl] sulfone and bis[3-(3,5-di-tert-butyl-2-hydroxybenzylideneamino)phenyl] sulfone were reacted to form the complexes with 2:1 copper:ligand ratio, Cu2[B(t-Bu) (OMe)BAPS](µ-OCH3)2 (4) and with 2:2 copper:ligand ratio, Cu2[B(t-Bu)2BAPS]2 (5), respectively. Structures of 4 and 5 were determined based on IR, UV-Vis, and FAB-MS data in comparison with previously characterized related copper complexes. The two complexes 4 and 5 were utilized in the oxidation of the substrates 2,4- and 2,6-di-tertbutylphenol (dtbp) at -50C with H2O2 in CH2Cl2. The coupling products are preferred in both cases. For 2,4-dtbp, yields of 4,600% and 7,200% of 3,3’,5,5’-tetra-tert-butyl-2,2’- biphenol were achieved with the use …


Stop Rotating! One Substitution Halts The B19- Motor, Francisco Cervantes-Navarro, Gerarso Martínez-Guajardo, Edison Osorio, Diego Moreno, William Tiznado, Rafael Islas, Kelling J. Donald, Gabriel Merino Jan 2014

Stop Rotating! One Substitution Halts The B19- Motor, Francisco Cervantes-Navarro, Gerarso Martínez-Guajardo, Edison Osorio, Diego Moreno, William Tiznado, Rafael Islas, Kelling J. Donald, Gabriel Merino

Chemistry Faculty Publications

The B19- anion and other boron species have been dubbed ‘Wankel motors’ for the almost barrierless rotation of inner and outer concentric rings relative to each other in these compounds. A single substitution in B19- is shown to shut down the well-established fluxionality in the anion. A carbon atom substituted in the structure to give a neutral CB18 species is shown computationally to enforce bond localization.


Metabolomic Analysis Of Liver Tissue From The Vx2 Rabbit Model Of Secondary Liver Tumors, R. Ibarra, J. E. Dazard, Y. Sandlers, F. Rehman, R. Abbas, R. Kombu, G. F. Zhang, H. Brunengraber, J. Sanabria Jan 2014

Metabolomic Analysis Of Liver Tissue From The Vx2 Rabbit Model Of Secondary Liver Tumors, R. Ibarra, J. E. Dazard, Y. Sandlers, F. Rehman, R. Abbas, R. Kombu, G. F. Zhang, H. Brunengraber, J. Sanabria

Chemistry Faculty Publications

Purpose. The incidence of liver neoplasms is rising in USA. The purpose of this study was to determine metabolic profiles of liver tissue during early cancer development. Methods. We used the rabbit VX2 model of liver tumors (LT) and a control group consisting of sham animals implanted with Gelfoam into their livers (LG). After two weeks from implantation, liver tissue from lobes with and without tumor was obtained from experimental animals (LT+/LT-) as well as liver tissue from controls (LG+/LG-). Peaks obtained by Gas Chromatography-Mass Spectrometry were subjected to identification. 56 metabolites were identified and their profiles compared between groups …


Rat Hippocampal Responses Up To 90 Days After A Single Nanoceria Dose Extends A Hierarchical Oxidative Stress Model For Nanoparticle Toxicity, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield Jan 2014

Rat Hippocampal Responses Up To 90 Days After A Single Nanoceria Dose Extends A Hierarchical Oxidative Stress Model For Nanoparticle Toxicity, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield

Chemistry Faculty Publications

Ceria engineered nanomaterials (ENMs) have very promising commercial and therapeutic applications. Few reports address the effects of nanoceria in intact mammals, let alone long term exposure. This knowledge is essential to understand potential therapeutic applications of nanoceria in relation to its hazard assessment. The current study elucidates oxidative stress responses in the rat hippocampus 1 and 20 h, and 1, 7, 30 and 90 days following a single systemic infusion of 30 nm nanoceria. The results are incorporated into a previously described hierarchical oxidative stress (HOS) model. During the 1-20 h period, increases of the GSSG: GSH ratio and cytoprotective …


A Loose Domain Swapping Organization Confers A Remarkable Stability To The Dimeric Structure Of The Arginine Binding Protein From Thermotoga Maritima, Alessia Ruggiero, Jonathan D. Dattelbaum, Maria Staiano, Rita Berisio, Sabato D'Auria, Luigi Vitagliano Jan 2014

A Loose Domain Swapping Organization Confers A Remarkable Stability To The Dimeric Structure Of The Arginine Binding Protein From Thermotoga Maritima, Alessia Ruggiero, Jonathan D. Dattelbaum, Maria Staiano, Rita Berisio, Sabato D'Auria, Luigi Vitagliano

Chemistry Faculty Publications

The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate …


Nicotine Exploits A Copi-Mediated Process For Chaperone-Mediated Up-Regulation Of Its Receptors, Brandon J. Henderson, Rahul Srinivasan, Weston A. Nichols, Crystal N. Dilworth, Diana F. Gutierrez, Elisha D. W. Mackey, Sheri Mckinney, Ryan M. Drenan, Christopher I. Richards, Henry A. Lester Dec 2013

Nicotine Exploits A Copi-Mediated Process For Chaperone-Mediated Up-Regulation Of Its Receptors, Brandon J. Henderson, Rahul Srinivasan, Weston A. Nichols, Crystal N. Dilworth, Diana F. Gutierrez, Elisha D. W. Mackey, Sheri Mckinney, Ryan M. Drenan, Christopher I. Richards, Henry A. Lester

Chemistry Faculty Publications

Chronic exposure to nicotine up-regulates high sensitivity nicotinic acetylcholine receptors (nAChRs) in the brain. This up-regulation partially underlies addiction and may also contribute to protection against Parkinson's disease. nAChRs containing the α6 subunit (α6* nAChRs) are expressed in neurons in several brain regions, but comparatively little is known about the effect of chronic nicotine on these nAChRs. We report here that nicotine up-regulates α6* nAChRs in several mouse brain regions (substantia nigra pars compacta, ventral tegmental area, medial habenula, and superior colliculus) and in neuroblastoma 2a cells. We present evidence that a coat protein complex I (COPI)-mediated process mediates this …


Amino Acid Region 1000–1008 Of Factor V Is A Dynamic Regulator For The Emergence Of Procoagulant Activity, Joesph R. Wiencek, Mahesheema Na, Jamila Hirbawi, Michael Kalafatis Dec 2013

Amino Acid Region 1000–1008 Of Factor V Is A Dynamic Regulator For The Emergence Of Procoagulant Activity, Joesph R. Wiencek, Mahesheema Na, Jamila Hirbawi, Michael Kalafatis

Chemistry Faculty Publications

Single chain factor V (fV) circulates as an Mr 330,000 quiescent pro-cofactor. Removal of the B domain and generation of factor Va (fVa) are vital for procoagulant activity. We investigated the role of the basic amino acid region 1000-1008 within the B domain of fV by constructing a recombinant mutant fV molecule with all activation cleavage sites (Arg(709)/Arg(1018)/Arg(1545)) mutated to glutamine (fV(Q3)), a mutant fV molecule with region 1000-1008 deleted (fV(ΔB9)), and a mutant fV molecule containing the same deletion with activation cleavage sites changed to glutamine (fV(ΔB9/Q3)). The recombinant molecules along with wild type fV (fV(WT)) were transiently expressed …


Lack Of Rnase L Attenuates Macrophage Functions, Xin Yi, Chun Zeng, Hongli Liu, Xiaoli Chen, Ping Zhang, Boo Seok Yun, Ge Jin, Aimin Zhou Dec 2013

Lack Of Rnase L Attenuates Macrophage Functions, Xin Yi, Chun Zeng, Hongli Liu, Xiaoli Chen, Ping Zhang, Boo Seok Yun, Ge Jin, Aimin Zhou

Chemistry Faculty Publications

Background: Macrophages are one of the major cell types in innate immunity against microbial infection. It is believed that the expression of proinflammatory genes such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL–6, and cyclooxygenase-2 (Cox-2) by macrophages is also crucial for activation of both innate and adaptive immunities. RNase L is an interferon (IFN) inducible enzyme which is highly expressed in macrophages. It has been demonstrated that RNase L regulates the expression of certain inflammatory genes. However, its role in macrophage function is largely unknown. Methodology: Bone marrow-derived macrophages (BMMs) were generated from RNase L+/+and −/− mice. The migration …