Chemistry Commons^™

A Galactomannoglucan Derived From Agaricus Brasiliensis: Purification, Characterization And Macrophage Activation Via Mapk And Ikappab/Nfkappab Pathways, Yanqing Zhang, Danting Liu, Leilei Fang, Xiaotong Zhao, Aimin Zhou, Junbo Xie

Chemistry Faculty Publications

In this study, a novel galactomannoglucan named as TJ2 was isolated from Agaricus brasiliensis with microwave extraction, macroporous resin, ion exchange resin and high resolution gel chromatography. TJ2 is composed of glucose, mannose and galactose in the ratio 99.2:0.2:0.6. Infrared spectra (IR), methylation analysis and nuclear magnetic resonance spectra indicated that TJ2 mainly contained a b-(1?3) – linked glucopyranosyl backbone. Interestingly, TJ2 significantly promoted RAW264.7 cell proliferation, and was able to activate the cells to engulf E. coli. In addition, TJ2 induced the expression of Interleukin 1b (IL-1b), Interleukin 6 (IL-6), tumor necrosis factor a (TNF-a) and cyclooxygenase-2 (Cox-2) in …

Facile Synthesis, Structure, Biocompatibility And Antimicrobial Property Of Gold Nanoparticle Composites From Cellulose And Keratin, Chieu D. Tran, Franja Prosenc, Mladen Franko

Chemistry Faculty Research and Publications

A novel, one-pot method was developed to synthesize gold nanoparticle composite from cellulose (CEL), wool keratin (KER) and chloroauric acid. Two ionic liquids, butylmethylimmidazolium chloride and ethylmethylimmidazolium bis(trifluoromethylsulfonyl)imide were used to dissolve CEL, KER and HAuCl₄. X-ray diffraction and X-ray photoelectron results show that Au³⁺ was completely reduced to Au⁰NPs with size of (5.5 ± 1) nm directly in the composite with NaBH₄. Spectroscopy and imaging results indicate that CEL and KER remained chemically intact and were homogeneously distributed in the composites with Au⁰NPs. Encapsulating Au⁰NPs into [CEL+KER] composite …

Investigation Of Temperature Response Of Photopolymer Material Used For Holographic Sensor, Muhammad Irfan Dr, Tatsiana Mikulchyk Dr, Suzanne Martin Dr, Izabela Naydenova Prof

Articles

Recently, functionalised photopolymer has emerged as a versatile recording material in the field of optical holography due to its novel characteristics and potential use in the development of holographic based sensors, and optical elements. This work describes the temperature response of a newly developed photopolymer, containing of a monomer Nisopropylacrylamide (NIPA) which under photopolymerisation forms a temperature sensitive polymer - Poly(Nisopropylacrylamide) (PNIPA). The photonic sensor was developed by holographic recording of volume phase transmission gratings in a self-processing NIPA-based polymer with a 532 nm laser beam. A 633 nm probe beam was used to monitor real time diffraction efficiency (DE) …

Cooperative Standing-Horizontalstanding Reentrant Transition For Numerous Solid Particles Under External Vibration, Satoshi Takatori, Hikari Baba, Takatoshi Ichino, Chwen-Yang Shew, Kenichi Yoshikawa

Publications and Research

We report the collective behavior of numerous plastic bolt-like particles exhibiting one of two distinct states, either standing stationary or horizontal accompanied by tumbling motion, when placed on a horizontal plate undergoing sinusoidal vertical vibration. Experimentally, we prepared an initial state in which all of the particles were standing except for a single particle that was placed at the center of the plate. Under continuous vertical vibration, the initially horizontal particle triggers neighboring particles to fall over into a horizontal state through tumbling-induced collision, and this effect gradually spreads to all of the particles, i.e., the number of horizontal particles …

Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter

Chemistry Faculty Publications

Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteinaceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions between htt …

A Dna-Conjugated Small Molecule Catalyst Enzyme Mimic For Site-Selective Ester Hydrolysis, Moira L. Flanagan, A. Emilia Arguello, Drew E. Colman, Jiyeon Kim, Jesse N. Krejci, Shimu Liu, Yueyu Yao, Yu Zhang, David J. Gorin

Chemistry: Faculty Publications

The challenge of site-selectivity must be overcome in many chemical research contexts, including selective functionalization in complex natural products and labeling of one biomolecule in a living system. Synthetic catalysts incorporating molecular recognition domains can mimic naturally-occurring enzymes to direct a chemical reaction to a particular instance of a functional group. We propose that DNA-conjugated small molecule catalysts (DCats), prepared by tethering a small molecule catalyst to a DNA aptamer, are a promising class of reagents for site-selective transformations. Specifically, a DNA-imidazole conjugate able to increase the rate of ester hydrolysis in a target ester by >100-fold compared with equimolar …

Computational Assessment Of An Elusive Aromatic N3p3 Molecule, Alyona A. Starikova, Natalia M. Boldyreva, Ruslan M. Minyaev, Alexander I. Boldyrev, Vladimir I. Minkin

Chemistry and Biochemistry Faculty Publications

We computationally proved that the planar aromatic hexagonal isomer N₃P₃ with the alteration of N and P is the second most stable structure for the N₃P₃ stoichiometry. We found that the aromatic isomer has high barriers for transition into the global minimum structure or into the three isolated NP molecules, making this structure kinetically stable. We showed that the sandwich N₃P₃CrN₃P₃ molecule corresponds to a minimum on the potential energy surface; thus, the aromatic N₃P₃ molecule has a potential to be a new ligand …

Aerogen Bonds Formed Between Aeof2 (Ae = Kr, Xe) And Diaziness: Comparisons Between Σ-Hole And Π-Hole Complexes, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The interaction between KrOF2 or XeOF2 and the 1,2, 1,3, and 1,4 diazines is characterized chiefly by a Kr/Xe···N aerogen bond, as deduced from ab initio calculations. The most stable dimers take advantage of the σ-hole on the aerogen atom, wherein the two molecules lie in the same plane. The interaction is quite strong, as much as 18 kcal mol-1. A second class of dimer geometry utilizes the π-hole above the aerogen atom in an approximate perpendicular arrangement of the two monomers; these structures are not as strongly bound: 6-8 kcal mol-1. Both sorts of dimers contain auxiliary CH···F H-bonds …

Detection And Characterization Of The Tin Dihydride (Snh2 And Snd2) Molecule In The Gas Phase, Tony C. Smith, Dennis J. Clouthier

Chemistry Faculty Publications

The SnH₂ and SnD₂ molecules have been detected for the first time in the gas phase by laser-induced fluorescence (LIF) and emission spectroscopic techniques through the ùB₁–X̃¹A₁ electronic transition. These reactive species were prepared in a pulsed electric discharge jet using (CH₃)₄Sn or SnH₄/SnD₄ precursors diluted in high pressure argon. Transitions to the electronic excited state of the jet-cooled molecules were probed with LIF, and the ground state energy levels were measured from single rovibronic level emission spectra. The LIF spectrum of SnD_{2 …}

Zb716, A Steroidal Selective Estrogen Receptor Degrader (Serd), Is Orally Efficacious In Blocking Tumor Growth In Mouse Xenograft Models., S. Guo, Changde Zhang, M. Bratton, M Mottamal, Jiawang Liu, Peng Ma, P. Ma, Shilong Zheng

Faculty and Staff Publications

Advances in oral SERDs development so far have been confined to nonsteroidal molecules such as those containing a cinnamic acid moiety, which are in earlystage clinical evaluation. ZB716 was previously reported as an orally bioavailable SERD structurally analogous to fulvestrant. In this study, we examined the binding details of ZB716 to the estrogen receptor alpha (ERα) by computer modeling to reveal its interactions with the ligand binding domain as a steroidal molecule. We also found that ZB716 modulates ERα-coregulator interactions in nearly identical manner to fulvestrant. The ability of ZB716 to inhibit cell growth and downregulate ER expression in endocrine …

Structural Tuning Of Boron Difluoride Formazanate Electrochemiluminescence Mediated By Tri-N-Propylamine, Mahdi Hesari, Stephanie M. Barbon, Rayner B. Mendes, Viktor N. Staroverov, Zhifeng Ding, Joe Gilroy

Chemistry Publications

Electrochemistry and electrogenerated chemiluminescence (ECL) of boron difluoride formazanate complexes bearing p-methoxyphenyl N-substituents were studied experimentally and computationally. It was shown that the substituents at the 3-position (R³) of the formazanate backbone play a critical role in the electrochemistry and ECL of the complexes in the presence of tri-n-propylamine (TPrA). The ECL emission of 1a (R³ = cyano), 1b (R³ = phenyl), and 1c (R³ = p-C₆H₄OMe) occurred at peak wavelengths of 724 nm (1.71 eV), 704 nm (1.76 eV), and 723 nm (1.71 eV), consistent …

Flavin-N5 Covalent Intermediate In A Nonredox Dehalogenation Reaction Catalyzed By An Atypical Flavoenzyme, Yumin Dai, Karina Kizjakina, Ashley C. Campbell, David A. Korasick, John J. Tanner, Pablo Sobrado

Chemistry Faculty Research & Creative Works

The flavin-dependent enzyme 2-haloacrylate hydratase (2-HAH) catalyzes the conversion of 2-chloroacrylate, a major component in the manufacture of acrylic polymers, to pyruvate. The enzyme was expressed in Escherichia coli, purified, and characterized. 2-HAH was shown to be monomeric in solution and contained a non-covalent, yet tightly bound, flavin adenine dinucleotide (FAD). Although the catalyzed reaction was redox-neutral, 2-HAH was active only in the reduced state. A covalent flavin-substrate intermediate, consistent with the flavin-acrylate iminium ion, was trapped with cyanoborohydride and characterized by mass spectrometry. Small-angle X-ray scattering was consistent with 2-HAH belonging to the succinate dehydrogenase/fumarate reductase family of flavoproteins. …

The Van Der Waals Fluid's Liquid Vapor Coexistence Locus, Carl W. David

Chemistry Education Materials

The liquid vapor coexistence locus is plotted from the analytical solution to the Maxwell construction for the van der Waals fluid.

Ruthenium Complexes Of The General Formula [Rucl 2 (Phox) 2 ] As Precatalysts In Propargylic Substitution Reactions, Negar Jourabchian, Kellsie Jurkowski, Eike Bauer

Chemistry & Biochemistry Faculty Works

After activation by chloride abstraction utilizing NaBArF as an activator (BArF = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate), a complex of the general formula [RuCl2 (PHOX)2 ] was utilized as a catalyst in propargylic substitution reactions, where PHOX is a phosphinooxazoline ligand. Oxygen and nitrogen-centered nucleophiles could be employed in the substitution of a propargylic acetate to obtain the corresponding propargylic substitution products in 87% to 9% isolated yields (45 °C, 16 h reaction time, toluene solvent, 1-2 mol% catalyst loading, 1-2 mol% activator). 

Analysis Of Veterinary Drug Residues In Imported And Domestic Crawfish Using Liquid Chromatography—Mass Spectrometry, Emily Kate Wall

LSU Master's Theses

Aquaculture production has greatly increased over the past few decades, and will continue to grow as the world fisheries become overfished and demand for seafood increases. With increased production comes more intense cultivation methods and heavy use of formulated feeds that may contain veterinary drug residues. Currently no antibiotics are allowed in the U.S. for crawfish aquaculture; yet, detectable levels of various antibiotics have been found in imported seafood samples.The FDA is responsible for testing aquaculture products entering the United States, but only has the capabilities to test a minimal amount of those imports. Additionally, for crawfish there is only …

E‑Cigarette Airflow Rate Modulates Toxicant Profiles And Can Lead To Concerning Levels Of Solvent Consumption, Tetiana Korzun, Maryana Lazurko, Tetiana Korzun, Ian Munhenzva, Kelley Barsanti, Yilin Huang, R. Paul Jensen, Jorge O. Escobedo, Wentai Luo, David H. Peyton, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Electronic cigarettes enabling enhanced airflow have grown in popularity in recent years. The objective of this study is to show that flow rates modulate the levels of specific aerosol toxicants produced in electronic cigarettes. Flow rates used in various laboratory investigations involving e-cigarettes have varied widely to date, and can thus promote interlaboratory variability in aerosol product profiles. The thermal decomposition of hydroxyacetone and glycolaldehyde is less favorable at lower temperatures, supporting the observations of these products at higher flow rates/lower heating coil temperatures. Higher temperatures promote the formation of acetaldehyde from hydroxyacetone and formaldehyde from both hydroxyacetone and glycolaldehyde. …

Spermidine-Regulated Biosynthesis Of Heat-Stable Antifungal Factor (Hsaf) In Lysobacter Enzymogenes Oh11, Yuan Chen, Fengquan Liu, Liangcheng Du

Liangcheng Du Publications

Heat-Stable Antifungal Factor (HSAF) and its analogs are antifungal natural products produced by the biocontrol agent Lysobacter enzymogenes. The production of HSAF is greatly influenced by environmental stimuli and nutrients, but the underlying molecular mechanism is mostly unclear. Here, we found that HSAF production in L. enzymogenes OH11 is strictly controlled by spermidine, which is the most prevalent triamine in bacteria. When added into OH11 cultures, spermidine regulated the production of HSAF and analogs in a concentration-dependent manner. To verify the role of spermidine, we deleted LeSDC and LeADC genes, encoding S-adenosylmethionine decarboxylase and arginine decarboxylase, respectively, that are the …

Structural Evolution Of Gold-Doped Bismuth Clusters AubiN– (N = 4−8), Seema Pande, Tian Jian, Navneet S. Khetrapal, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The structures of gold-doped bismuth clusters, AuBi_n⁻ (n = 4−8), are investigated through a joint photoelectron spectroscopy and density functional theory (DFT) study. Well-resolved photoelectron spectra are obtained at several photon energies. Global minimum searches coupled with DFT calculations yield low-lying structures, whose relative energies are further evaluated by single-point energy calculations at the CCSD(T) level of theory. Vertical detachment energies are calculated with the inclusion of spin−orbit effects to compare with the experimental data. Three-dimensional structures are found to be dominant in this size range, while a planar low-lying isomer is observed only for AuBi_{4 …}

Electrokinetic Flow Of Aqueous Electrolyte In Amorphous Silica Nanotubes, Chris D. Daub, Natalie Cann, D. Bratko, Alenka Luzar

Chemistry Publications

We study the pressure-driven flow of aqueous NaCl in amorphous silica nanotubes using nonequilibrium molecular dynamics simulations featuring both polarizable and non-polarizable molecular models. Different pressures, electrolyte concentrations and pore sizes are examined. Our results indicate a flow that deviates considerably from the predictions of Poiseuille fluid mechanics. Due to preferential adsorption of the different ionic species by surface SiO! or SiOH groups, we find that a significant electric current is generated, but with opposite polarities using polarizable vs. fixed charge models for water and ions, emphasizing the need for careful parameterization in such complex systems. We also examine the …

Curvature Dependence Of The Effect Of Ionic Functionalization On The Attraction Among Nanoparticles In Dispersion, B. Shadrack Jabes, D. Bratko, Alenka Luzar

Chemistry Publications

Solubilization of nanoparticles facilitates nanomaterial processing and enables new applications. An effective method to improve dispersibility in water is provided by ionic functionalization.We explore how the necessary extent of functionalization depends on the particle geometry. Using molecular dynamics/umbrella sampling simulations, we determine the effect of the solute curvature on solventaveraged interactions among ionizing graphitic nanoparticles in aqueous dispersion. We tune the hydrophilicity of molecular-brush coated fullerenes, carbon nanotubes, and graphane platelets by gradually replacing a fraction of the methyl end groups of the alkyl coating by the ionizing –COOK or –NH3Cl groups. To assess the change in nanoparticles’ dispersibility in …

High-Resolution Infrared Spectroscopy Of The V18 And V26 Bands Of Trans-1,3-Pentadiene, Minh Tran

Chemistry Honors Papers

A high-resolution absorbance spectrum of trans-1,3-pentadiene was obtained using a quantum cascade laser-based spectrometer. All spectra were calibrated using a methanol reference spectrum generated by SpectraPlot using the HITRAN Database. The frequency uncertainty is estimated as 0.002 cm^-1. Two peaks at 976.69 and 1003.50 cm^-1 were assigned to ν₁₈ and ν₂₆ bands respectively. Supporting calculations of the anharmonic vibrational frequencies and rotational constants were performed at the MP2/cc-pVTZ level of theory. Two specific motions were assigned to the vibrational modes ν₁₈ and ν₂₆. A spectrum of the ν₂₆ band was …

High-Resolution Infrared Spectroscopy Of The V23 And V22 Vibrational Bands Of Methyl Vinyl Ketone, Michael Iranpour

Chemistry Honors Papers

The high-resolution Infrared spectrum of methyl vinyl ketone (C4H6O) has been acquired in the region containing the v₂₂ and v₂₃ bands near 987 cm^-1 and 1001cm^-1, respectively, using a quantum cascade laser-based spectrometer. All acquired spectra underwent frequency calibrations that will prove useful during future atmospheric measurements of methyl vinyl ketone. Anharmonic calculations were performed at the MP2/ccp-pVTZ level of theory to obtain the vibrational frequencies and the excited state rotational constants of cis-methyl vinyl ketone. These calculations supported the assignment of the Q-branch features at 1001.031 and 987.592 cm^-1 to the v …

Synthesis, Structure And Reactivity Of Heterobimetallic Complexes For Small Molecule Activation And Catalysis, Amelie Nicolay

Link Foundation Energy Fellowship Reports

Society remains tied to fossil fuels while increasing pressure on the climate suggests a transition to renewable energy resources. However, the efficiency of processes enabling such a transition has considerable room for improvement. Relevantly, natural systems have evolved enzymes that enable a very efficient conversion of small molecules such as H2, CO and CO2,1 and perform these conversions more selectively and under milder conditions than current industrial processes. Many of these enzymes rely on multimetallic, and often heterometallic, active sites of abundant transition metals, for example in [NiFe] or [CuMo] carbon monoxide dehydrogenases.2 In addition, close proximity between metal centers …

Biomimetic Macromolecules For Macrophage Targeting And Modulation, Joshua Whited

ETD Archive

Carbohydrate recognition has come to the forefront of biological aiming to uncover the mechanisms of physiological and pathological processes. Cell surface glycans are involved in processes including cellular adhesion, cell signaling, and immune response. A new approach for profiling cell surface glycans has great potential for a wide range of biomedical applications. Lectins have been conventionally used to determine the structure and function of glycoproteins, however, their numbers are still restricted compared to the number of glycan structures. Boronic acid has proven a remarkable small molecule capable of binding diols in aqueous solution. This interaction indicates boronic acid derived molecules …

Oxidation Of Ferrocene Derivatives With Dibenzoyl Peroxide And Meta-Chloroperoxybenzoic Acid, Jos M. Halstead

ETD Archive

The chemical oxidation of ferrocene and related derivatives (RFc) via organic peroxides solvated in acetonitrile was studied spectrophotometrically by varying concentration and temperature to determine kinetics and activation parameters. The reaction rate of ferrocene with dibenzoyl peroxide depends strongly on whether electron withdrawing or donating substituents are present. Products were analyzed and the effect of different solvents on reactivity were studied. The rate law was first order in both oxidant and reductant, and steric and solvent effects are consistent with outer sphere electron transfer (ET) as the rate-controlling step. B3YLP calculations were conducted to determine reorganization energies using Marcus theory …

Digital Design And Fabrication Of An Atmospheric Aerosol Impactor Using A Formlabs Form 2 Sla 3d Printer, Stefan Vincent

CUP Undergraduate Research

Atmospheric aerosol (AA) particles are defined as solid or liquid particles suspended in the air. AA particles smaller than 10 μm in diameter are small enough to bypass the upper respiratory system which functions as a filter for harmful substances entering the lungs. AA particles can be collected using a device called an aerosol impactor. After collection, the particles can be analyzed offline for chemical composition using a variety of analytical techniques. The weight of a commercially manufactured AA particle impactor poses an issue if attached to a mobile AA particle sampling platform such as an unmanned aerial vehicle (UAV). …

Audiobook Of A World From Dust, Ben Mcfarland

Faculty Open Access Books

A World From Dust is a popular science book about the chemical sequence behind the evolution of creation.

It’s about how geology, biology, and chemistry worked together over billions of years, providing a hidden order under the random flow of genes and lava and water.

It’s about the chemical job that each element takes up in life, and how that job is predictable from its place on the periodic table.

It can be told as the story of many elements: how iron and sulfur gave a spark of life; how manganese was a key for oxygen; and how copper and …

X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl, Jackson Earl

STAR Program Research Presentations

The first aspect of this research project focuses on investigating the surface chemistry of high pressure high temperature (HPHT) nanodiamond by using X-ray spectroscopy techniques at the Stanford Synchrotron Radiation Lightsource (SSRL). HPHT nanodiamond is being examined as a biosensing tool for electric field detection based on the fluorescent nitrogen vacancy center hosted within diamond. With use of the transition edge spectrometer (TES), a state-of-the-art X-ray fluorescence detector, we are able to probe the surface and bulk properties of diamond. Preliminary work using density functional theory (DFT) has been done, offering insight into ground state energies and electronic structure. DFT …

Probing The Surface Of Nanodiamonds At Stanford Synchrotron Radiation Lightsource And San Jose State University, Jocelyn Valenzuela, Jackson Earl, Cynthia Melendrez, Grace Jeanpierre, Dennis Nordlund, Abraham Wolcott

STAR Program Research Presentations

The nitrogen-vacancy center in diamond is a promising tool in oncology, electric field sensing, and quantum cryptography. High-pressure high-temperature (HPHT) nanodiamonds (NDs) are prime contenders for these fields because they host nitrogen-vacancy centers (NVCs) which are applicable towards cancer detection and electric and magnetic field sensing. However, to apply HPHT NDs to these fields, the surface must first be functionalized—a difficult process because of the inert nature of the surface. The project at hand focuses on surface modification of HPHT NDs with amines to allow for further bioconjugation of small molecules and plasmonic shells. This is done via liquid-phase chemistry …

Large Effect Quantitative Trait Loci For Salicinoid Phenolic Glycosides In Populus: Implications For Gene Discovery, Scott A. Woolbright, Brian J. Rehill, Richard L. Lindroth, Stephen P. Difazio, Gregory D. Martinsen, Matthew S. Zinkgraf, Gerard J. Allan, Paul Keim, Thomas G. Whitham

Faculty & Staff Scholarship

Genomic studies have been used to identify genes underlying many important plant secondary metabolic pathways. However, genes for salicinoid phenolic glycosides (SPGs)—ecologically important compounds with significant commercial, cultural, and medicinal applications—remain largely undescribed. We used a linkage map derived from a full-sib population of hybrid cottonwoods (Populus spp.) to search for quanti- tative trait loci (QTL) for the SPGs salicortin and HCH-salicortin. SSR markers and primer sequences were used to anchor the map to the V3.0 P. trichocarpa genome. We discovered 21 QTL for the two traits, including a major QTL for HCH-salicortin (R2 = .52) that colocated with a …