Physical Sciences and Mathematics Commons^™

Generating Long-Lasting ¹H And ¹³C Hyperpolarization In Small Molecules With Parahydrogen-Induced Polarization, Thorsten Jonischkeit, Ute Bommerich, Jorg Stadler, Klaus Woelk, Heiko G. Niessen, Joachim Bargon

Chemistry Faculty Research & Creative Works

Recently, Levitt and co-workers demonstrated that conserving the population of long-lasting nuclear singlet states in weak magnetic fields can lead to a preservation of nuclear spin information over times substantially longer than governed by the (high-field) spin-lattice relaxation time T₁. Potential benefits of the prolonged spin information for magnetic resonance imaging and spectroscopy were pointed out, particularly when combined with the parahydrogen induced polarization (PHIP) methodology. In this contribution, we demonstrate that an increase of the effective relaxation time by a factor up to three is achieved experimentally, when molecules hyperpolarized by PHIP are kept in a weak …

Mechanisms Imposing The Vbeta Bias Of V14a Natural Killer T Cells And Consequences For Microbial Glycolipid Recognition, Paul B. Savage, Dasten G. Wei, Shane A. Curran, Luc Teyton, Albert Bendelac

Faculty Publications

Mouse and human natural killer T (NKT) cells recognize a restricted set of glycosphingolipids presented by CD1d molecules, including self iGb3 and microbial alpha-glycuronosylceramides. The importance of the canonical Valpha 14-Jalpha18 TCR alphachain for antigen recognition by NKT cells is well recognized, but the mechanisms underlying the Vbeta8, Vbeta7, and Vbeta2 bias in mouse have not been explored. To study the influences of thymic selection and the constraints of pairing with Valpha 14-Jalpha 18, we have created a population of mature T cells expressing Valpha 14-Jalpha 18 TCRalpha chain in CD1d-deficient mice and studied its recognition properties in vitro and …

Investigations Of Poly[(Styrene-Co-P-Methylstyrene)-Risobutylene- R-(Styrene-Co-P-Methylstyrene)] And Poly[(Acrylic Acid)-5-Styrene-Jb-Is0butylene-5-Styrene-Jb-(Acrylic Acid)], James Grabill Kopchick

Dissertations

The pMe study was conducted to understand the morphological and physical property changes that occur as the ratio of pMe to styrene is increased, effectively increasing the aliphatic units. By the introduction of pMe, the interface region becomes more blended/compatible as the pMe migrates to the interface. These pMe groups are theorized in effect to create multiple ‘anchors’ to distribute the loads experienced at the interface more effectively creating a synergistic effect on the final properties of the copolymers. The primary goals of the pentablock study were the characterization of unique membranes as related to …

Faithful Estimation Of Dynamics Parameters From Cpmg Relaxation Dispersion Measurements, Evgueni Kovriguine, James G. Kempf, Michael J. Grey, J. Patrick Loria

Chemistry Faculty Research and Publications

This work examines the robustness of fitting of parameters describing conformational exchange (k_ex, p_a/b, and Δω) processes from CPMG relaxation dispersion data. We have analyzed the equations describing conformational exchange processes for the intrinsic inter-dependence of their parameters that leads to the existence of multiple equivalent solutions, which equally satisfy the experimental data. We have used Monte-Carlo simulations and fitting to the synthetic data sets as well as the direct 3-D mapping of the parameter space of k_ex, p_a/b, and Δω to quantitatively assess …

Characterization Of The Transition State Of Functional Enzyme Dynamics, Evgueni Kovriguine, J. Patrick Loria

Chemistry Faculty Research and Publications

Through characterization of the solvent isotope effect on protein dynamics, we have examined determinants of the rate limitation to enzyme catalysis. A global conformational change in Ribonuclease A limits the overall rate of catalytic turnover. Here we show that this motion is sensitive to solvent deuterium content; the isotope effect is 2.2, a value equivalent to the isotope effect on the catalytic rate constant. We further demonstrate that the protein motion possesses a linear proton inventory plot, indicating that a single proton is transferred in the transition state. These results provide compelling evidence for close coupling between enzyme dynamics and …

Platinum(Ii) Diimine Diacetylides: Metallacyclization Enhances Photophysical Properties, Fei Hua, Solen Kinayyigit, John R. Cable, Felix N. Castellano

Chemistry Faculty Publications

The synthesis, structural characterization, and photoluminescence properties of a new platinum(II) diimine complex bearing the bidentate diacetylide ligand tolan- 2,2'-diacetylide (tda), Pt(dbbpy)( tda) [dbbpy) = 4,4'-di-tert-butyl-2,2'-bipyridine], are described. In CH2Cl2, Pt( dbbpy)( tda) exhibits a strong visible charge-transfer absorption and broad emission centered at 562 nm. The photoluminescence quantum yield and excited-state lifetime are 0.52 and 2.56 mu s, respectively, at room temperature. These parameters indicate that the planarization and rigidity introduced by the cyclic diacetylide leads to a lower-energy-absorbing species displaying enhanced photophysics relative to the analogous Pt( dbbpy)( C = CPh)(2). Time-dependent density functional theory calculations, which include …

Structural And Magnetic Investigations Of Cs2Agf4 And Its Doped Derivatives, Michelle Renee Dolgos

Masters Theses

This thesis describes the structural and magnetic properties of solid state silver fluorides such as Cs₂AgF₄ and its doped derivatives. A wide range of techniques such as X-ray and neutron diffraction, susceptibility measurements and inelastic neutron scattering experiments are used to characterize these materials. Silver fluorides are important given their strongly correlated magnetic behavior and the potential to discover a new class of high T_C materials. Few studies have been done on silver (II) fluorides as their characterization has been problematic due to their inherent air and water sensitivity. This study is the first to accurately …

Novel Materials Used In Hydrogen Energy Economy, Hongliang Zhou

Masters Theses

The purpose of this study was to do some efforts in developing some novel polymer materials which could have the potential use in hydrogen pipelines and PEM fuel cell.

In the project of developing hydrogen pipelines, sulfonated PET, sulfonated PET/Clay and PET/Clay were produced by the method of solvent-mixing. Characterizations with TEM, SAXS were made to determine the exfoliation degree of nanocomposites. TGA was carried out to measure the thermal stability, and hydrogen permeability was also taken in order to measure the H2 gas barrier performance. It was found that the addition of clay into S-PET or PET could decrease …

Peroxyl Radical Clocks, Bill Roschek, Keri A. Tallman, Christopher L. Rector, Jason G. Gillmore, Derek A. Pratt, Carlo Punta, Ned A. Porter

Faculty Publications

A series of peroxyl radical clocks has been developed and calibrated based on the competition between the unimolecular β-fragmentation (kβ) of a peroxyl radical and its bimolecular reaction with a hydrogen atom donor (kH). These clocks are based on either methyl linoleate or allylbenzene and were calibrated directly with α-tocopherol or methyl linoleate, which have well-established rate constants for reaction with peroxyl radicals (kH-tocopherol = 3.5 × 106 M-1 s-1, kH-linoleate = 62 M-1 s-1). This peroxyl radical clock methodology has been successfully applied to determine inhibition and propagation rate constants ranging from 100 to 107 M-1 s-1.

Nocturnal Odd-Oxygen Budget And Its Implications For Ozone Loss In The Lower Troposphere, Steven S. Brown, J. A. Neuman, T. B. Ryerson, M. Trainer, W. P. Dubé, J. S. Holloway, C. Warneke, J. A. De Gouw, Stephen G. Donnelly Ph.D., E. Atlas, B. Matthew, A. M. Middlebrook, R. Peltier, R. J. Weber, A. Stohl, J. F. Meagher, F. C. Fehsenfeld, A. R. Ravishankara

Chemistry Faculty Publications

Nitrogen oxides are important to the regulation of ozone throughout the Earth's atmosphere. Of particular interest for regional air quality is photochemical production and nocturnal destruction Of O3 in the lower troposphere in high NOx(=NO + NO2) environments. Nocturnal tropospheric odd oxygen (Ox), defined as O3 + NO2 + 2NO3 + 3N2O5, is used to assess the impact of NOx emissions on nocturnal O3 loss. Recent aircraft measurements of the components of Ox and HNO3 yield a detailed accounting of the nocturnal Ox budget in a regionally polluted environment. The analysis demonstrates the role of NO3 and N2O5 reactions in …

Protein Structure Similarity Clustering: Dynamic Treatment Of Pdb Structures Facilitates Clustering, Bradley D. Charette, Richard G. Macdonald, Stefan Wetzel, David B. Berkowitz, Herbert Waldmann

David Berkowitz Publications

Protein structure similarity clustering (PSSC) [1]– [3] is one of a number of potential guiding principles [4], [5] that have been introduced to focus combinatorial-library design/ protein targeting. PSSC clusters protein targets with similar ligand-binding cores in which little sequence or functional similarity is evident. Lead compounds for one member of the cluster then provide novel starting points in chemical space for ligand development for other members of the PSSC.

We describe herein a new clustering procedure that lends itself to ligand docking, molecular dynamics (MD), and the vector-alignment-search-tool (VAST) [6] algorithm. This MD-assisted approach offers an alternative to the …

Biochemical Characterization Of The Major Sorghum Grain Peroxidase, Mamoudou H. Dicko, Harry Gruppen, Riet Hilhorst, Alphons G. J. Voragen, Willen W. H. Van Berkel

Pr. Mamoudou H. DICKO, PhD

Dactinomycin Impairs Cellular Respiration And Reduces Accompanying Atp Formation, Zhimin Tao, Syed S. Ahmad, Harvey S. Penefsky, Jerry Goodisman, Abdul Kader Souid

Chemistry - All Scholarship

The effect of dactinomycin on cellular respiration and accompanying ATP formation was investigated in Jurkat and HL-60 cells. Cellular mitochondrial oxygen consumption (measured by a homemade phosphorescence analyzer) and ATP content (measured by the luciferin-luciferase bioluminescence system) were determined as functions of time t during continuous exposure to the drug. The rate of respiration, k, was the negative of the slope of [O2] versus t. Oxygen consumption and ATP content were diminished by cyanide, confirming that both processes involved oxidations in the mitochondrial respiratory chain. In the presence of dactinomycin, k decreased gradually with t, the decrease being more pronounced …

Identification Of The Binding Region Of The [2fe-2s] Ferredoxin In Stearoyl-Acyl Carrier Protein Desaturase: Insight Into The Catalytic Complex And Mechanism Of Action, Pablo Sobrado, Karen S. Lyle, Steven P. Kaul, Michelle M. Turco, Ida Arabshahi, Ashok Marwah, Brian G. Fox

Chemistry Faculty Research & Creative Works

Stearoyl-acyl carrier protein desaturase (Δ9D) catalyzes the O 2 and 2e- dependent desaturation of stearoyl-acyl carrier protein (18:0-ACP) to yield oleoyl-ACP (18:1-ACP). The 2e- are provided by essential interactions with reduced plant-type [2Fe-2S] ferredoxin (Fd). We have investigated the protein-protein interface involved in the Fd-Δ9D complex by the use of chemical cross-linking, site-directed mutagenesis, steady-state kinetic approaches, and molecular docking studies. The treatment of the different proteins with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxy succinimide revealed that carboxylate residues from Fd and lysine residues from Δ9D contribute to cross-linking. The single substitutions of K60A, K56A, and K230A on Δ9D decreased the k …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report January-March 2006, Spencer M. Steinberg

Separations Campaign (TRP)

Project Highlights:

• Established that iodide can be oxidized by MnO₂ to I₂ at pHs of 4-8 and moderate temperature.

• Demonstrated that p-hydroxybenzoic acid can be iodinated by MnO₂ and KI at pHs of 2-8.

• Established that humic acids can be iodinated by MnO₂ and iodide at room temperature in pH range of 4-8.

Gas-Phase Products And Secondary Aerosol Yields From The Ozonolysis Of Ten Different Terpenes, Anita Lee, Allen H. Goldstein, Melita D. Keywood, Song Gao, Varuntida Varutbangkul, Roya Bahreini, Nga L. Ng, Richard C. Flagan, John H. Seinfeld

Chemistry and Physics Faculty Articles

The ozonolyses of six monoterpenes (α-pinene, β-pinene, 3-carene, terpinolene, α-terpinene, and myrcene), two sesquiterpenes (α-humulene and β-caryophyllene), and two oxygenated terpenes (methyl chavicol and linalool) were conducted individually in Teflon chambers to examine the gas-phase oxidation product and secondary organic aerosol (SOA) yields from these reactions. Particle size distribution and number concentration were monitored and allowed for the calculation of the SOA yield from each experiment, which ranged from 1 to 54%. A proton transfer reaction mass spectrometer (PTR-MS) was used to monitor the evolution of gas-phase products, identified by their mass to charge ratio (m/z). …

9-Ethyl-3-(9h-9-Ethyl­Carbazol-3-Yl)-4-Nitro­-9h-Carbazole, Erol Asker, John Masnovi

Chemistry Faculty Publications

In the mol­ecule of the title compound, C₂₈H₂₃N₃O₂, the nitro group is almost perpendicular to the carbazole ring to which it is attached. The crystal packing is determined by C—H⋯O and π–π inter­actions, where the nitrated carbazole ring of one mol­ecule associates in a shifted parallel planar orientation with the centrosymmetrically related non-nitrated carbazole ring of a neighbouring mol­ecule.

Bis(9-Ethyl­Carbazol-3-Yl)Ethane, Erol Asker, John Masnovi

Chemistry Faculty Publications

In the title compound, C₃₀H₂₈N₂, each carbazole skeleton is essentially planar. The planes of the two carbazole ring systems are nearly parallel, with a dihedral angle of 2.33 (19)°. The crystal packing is stabilized only by van der Waals forces and weak C—H⋯π inter­actions.

Erratum: "Hard Sphere Radial Distribution Function Again", Andrij Trokhymchuk, Douglas Henderson, Ivo Nezbeda, Jan Jirsak

Faculty Publications

Some misprints have been found for parameters given by Eqs. 29 and 30 and the relevant equations in the Appendix.

Two New Resorcinarenes: A Pyridine & Acetic Acid Ligand For Metal Coordination And A Deep-Cavity Nitroquinoxaline Resorcinarene, Samantha Sizemore Vernetti

Theses and Dissertations

Functionalizing the upper rim of resorcinarene-based cavitands allows a variety of compounds to be synthesized from a single scaffold. Using the upper-rim moieties as ligands for a variety of transition metal ions further increases the versatility of this class of host compounds. A new resorcinarene-based molecule functionalized with four pyridine and acetic acid ligands has been successfully prepared to explore the properties of metal-assembled complexes. To synthesize this compound, tetra(bromomethyl)cavitand was reacted with N-(2-pyridylmethyl)-N-ethylacetate amine to give ethyl acetate pyridine resorcinarene. Hydrolysis of the ester gave acetic acid pyridine resorcinarene (APRes) in good yield. Complexes with Cu2+, Co2+, and Zn2+ …

2nd Annual Undergraduate Research Conference Abstract Book, University Of Missouri--Rolla

Undergraduate Research Conference at Missouri S&T

No abstract provided.

Chemo-Enzymatic Route To Synthesis Of Biodegradable Polymers And Glycolipid Analogs, Surbhi Bhatt

USF Tampa Graduate Theses and Dissertations

New catalytic synthetic methods in organic chemistry that satisfy increasingly stringent environmental constraints are in great demand by the pharmaceutical and chemical industries. Studies over last 15 years have revealed that activity of enzymes can be increased in organic solvents rather than their natural aqueous environment. Because of their ease of use, high selectivity and environment friendliness, enzymes are enjoying increasing popularity in today's synthesis world.

Chapter 1 describes chemo-enzymatic synthesis of various glycolipid analogs. A highly regioselective macrolactonization was achieved using lipase from Candida antarctica as a catalyst. It also describes evaluation of lipases from different source and their …

Α-Vinylic Amino Acids: Occurrence, Asymmetric Synthesis, And Biochemical Mechanisms, David B. Berkowitz, Bradley D. Charette, Kannan Karukurichi, Jill M. Mcfadden

David Berkowitz Publications

This report presents an overview of the family of naturally occurring “vinylic” amino acids, namely those that feature a C–C double bond directly attached to the α-carbon, along the side chain. Strategies that have been brought to bear on the stereo-controlled synthesis of these olefinic amino acids are surveyed. The mechanistic diversity by which such “vinylic triggers” can be actuated in a PLP (pyridoxal phosphate) enzyme active site is then highlighted by discussion of vinylglycine (VG), its substituted congeners, particularly AVG [4E-(2′-aminoethoxy)vinylglycine], and a naturally occurring VG-progenitor, SMM [(S)-methylmethionine].

Making Soap From Readily Available Agricultural And Household Wastes Can Increase Cleanless In Rural Area, Eugenia Lucas, Thomas Ciaglo

Student Research Posters

In some areas of the world, soap is too expensive for many people to afford. For these people an alternative exists. They can make their own soap. In general, soap is made by the reaction of triglycerides and caustic soda. However, caustic soda, too, may be difficult to find or too expensive. The aim of this project is to develop a process for making soap from readily available agricultural and household waste materials, and other inexpensive chemicals. By using this process, rural people can get the benefits of readily available, inexpensive soap. Soap is made from animal fats or vegetable …

Structures And Relative Stability Of Medium-Sized Silicon Clusters. V. Low-Lying Endohedral Fullerenelike Clusters Si31–Si40 And Si45, Soohaeng Yoo, N. Shao, C. Koehler, T. Fraunhaum, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We have performed unconstrained search for low-lying structures of medium-sized silicon clusters Si₃₁–Si₄₀ and Si₄₅, by means of the minimum-hopping global optimization method coupled with a density-functional based tight-binding model of silicon. Subsequent geometric optimization by using density-functional theory with the PBE, BLYP, and B3LYP functionals was carried out to determine the relative stability of various candidate low-lying silicon clusters obtained from the unconstrained search. The low-lying characteristics of these clusters can be affirmed by comparing the binding energies per atom of these clusters with previously determined lowest-energy clusters (Si_n) in the size …

Chemistry & Biochemistry Newsletter, Department Of Chemistry & Biochemistry, South Dakota State University

Chemistry & Biochemistry Newsletter: 2002-2015

Inside:

Page 2-4 Campus Mass Spectrometry Facility

Page 4 Alumni News

Page 5 Alum Featured; Scholarships and Awards

Page 6 Two New Departmental Scholarships; Recent Faculty Publications; Funding

Page 7 2006 Chemistry and Biochemistry Graduates

Manipulating Polar Ferromagnetism In Transition Metal Doped Zno: Why Manganese Is Different From Cobalt, Kevin R. Kittilstved, D. R. Gamelin

Kevin R. Kittilstved

High-temperature magnetic ordering in Mn2+- and Co2+-doped ZnO diluted magnetic semiconductors has been predicted theoretically and confirmed experimentally to have different charge-carrier requirements. This paper summarizes some of these experimental and theoretical results and relates the different carrier polarity requirements for 300 K ferromagnetism in Mn2+:ZnO and Co2+:ZnO to differences in the charge-transfer electronic structures of these two materials.

Synthesis Of Aspernigrin A, Erica Joerger

Undergraduate Theses and Capstone Projects

Aspernigrin A is a compound correlated with inhibiting the growth of cancer cells in the colon. A five-step synthesis was designed for aspernigrin A, projected to yield four intermediates and the final product. The intermediates were analyzed by high field 1HNMR and FT-IR spectroscopy before proceeding to the next step. A model pyridone ring system was successfully prepared from a commercially available pyrone precursor in two steps. These results provide a proof of concept that the synthetic scheme should successfully yield the natural product.

Relative Stability Of Planar Versus Double-Ring Tubular Isomers Of Neutral And Anionic Boron Cluster B20 And B20-, Wei An, Satya S. Bulusu, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

High-level ab initio molecular-orbital methods have been employed to determine the relative stability among four neutral and anionic B20 isomers, particularly the double-ring tubular isomer versus three low-lying planar isomers. Calculations with the fourth-order Møller-Plessset perturbation theory [MP4(SDQ)] and Dunning’s correlation consistent polarized valence triple zeta basis set as well as with the coupled-cluster method including single, double, and noniteratively perturbative triple excitations and the 6-311G(d) basis set show that the double-ring tubular isomer is appreciably lower in energy than the three planar isomers and is thus likely the global minimum of neutral B20 cluster. In contrast, calculations …

Protein–Protein Interactions Of Tandem Affinity Purification-Tagged Protein Kinases In Rice, Jai S. Rohila, Mei Chen, Shuo Chen, Johann Chen, Ronald Cerny, Chris Dardick, Patrick Canlas, Xia Xu, Michael Gribskov, Siddhartha Kanrar, Jian-Kang Zhu, P C. Ronald, Michael E. Fromm

Ronald Cerny Publications

Forty-one rice cDNAs encoding protein kinases were fused to the tandem affinity purification (TAP) tag and expressed in transgenic rice plants. The TAP-tagged kinases and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by mass spectrometry. Ninety-five percent of the TAP-tagged kinases were recovered. Fifty-six percent of the TAP-tagged kinases were found to interact with other rice proteins. A number of these interactions were consistent with known protein complexes found in other species, validating the TAP-tag method in rice plants. Phosphorylation sites were identified on four of the kinases that interacted with either …