Chemistry Commons^™

Glutathione: A Small Molecule With Big Sense, Cristina E. Raya, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Glutathione, a peptide found in microbes, plants and animals including human plays a key role in maintaining healthy cells. The peptide exists in both reduced and oxidized forms. Synthesis of GSH occurs in the cytosol of cells, and the extent of glutathione synthesis relies on various factors, such as amino acid availability, protein activity etc. Once synthesized, glutathione exists in both forms: oxidized (GSSG) and reduced (GSH). Oxidized glutathione characterized by its disulfide linkage. On the other hand, presence of a thiol group characterizes the reduced glutathione. This thiol makes the tripeptide an essential component of health; it makes glutathione …

Crystal Structures Of 2-Bromo-1,1,1,3,3,3-Hexa­Methyl-2-(Tri­Methyl­Sil­Yl)Tris­Ilane And 2-Bromo-1,1,1,3,3,3-Hexa­Isopropyl-2-(Triiso­Propyl­Sil­Yl)Tri­Silane, Eva Gulotty, Richard Staples, Shannon Biros, Peter Gaspar, Nigam Rath, William Winchester

Chemistry & Biochemistry Faculty Works

The synthesis and crystal structures of two tris­(tri­alkyl­sil­yl)silyl bromide compounds, C9H27BrSi4 (I, HypSiBr) and C27H63BrSi4 (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexa­methyl-2-(tri­methyl­sil­yl)tris­ilane using bromo­butane and 2,2′-azobis(2-methyl­propio­nitrile) as a radical initiator at 333 K. The mol­ecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si—Br bond distance is 2.2990 (12) Å and the Si—Si bond lengths are 2.3477 (8) Å. The Br—Si—Si bond angles are 104.83 (3)° and the Si—Si—Si bond angles are 113.69 (2)°, reflecting the steric hindrance …

A System For Conducting Laser-Induced Fluorescence Measurements On Gas Mixtures Exposed To Alpha Radiation, Patrick Ables

Master's Theses

This paper documents modifications to an existing vacuum system to allow laser-induced fluorescence spectroscopy measurements within simulated atmospheres under a variety of conditions. This added capability will expand the laboratory’s ability to experimentally validate a computational model that calculates the effects of radiation within the atmosphere. The computational model could reveal radiation-induced chemical products that can be used to develop an alternative detection method that can be implemented from a safe distance. The selection of molecules for experimental validation has been limited to those which can be detected utilizing cavity ringdown spectroscopy. The current model indicates nitric oxide and ozone …

Working With Organic Peroxides In The Academic Lab, Patrick Dussault

Organic Peroxides: Safety Issues

ABSTRACT: The following is a brief introduction to peroxide safety from the viewpoint of a synthetic chemist. Major topics include: classes of organic peroxides; peroxide reactivity; hazard identification and minimization; reaction monitoring; and, hazards associated with auto-oxidation of peroxidizable solvents.

KEYWORDS: peroxide, hydroperoxide, hydroperoxyacetal, ozonide, perester, dihydroperoxide, monoperoxyacetal, active oxygen, peroxide strips, TLC indicator, self-accelerating decomposition, radical, exothermicity, transition metals.

CONTENTS: 1. Literature resources 2. Major classes of peroxides 3. Basis for peroxide reactivity 4. Determining reactivity and minimizing hazards a. Steps to take before an experiment b. Minimizing hazard during reactions c. Monitoring reactions d. Working with isolated peroxides …

Collisional Quenching Of Highly Excited H2 Due To H2 Collisions, Yier Wan, B. H. Yang, P. C. Stancil, Balakrishnan Naduvalath, Nikhil J. Parekh, R. C. Forrey

Chemistry and Biochemistry Faculty Research

Rate coefficients for pure rotational quenching in H2(ν 1 = 0, j 1) + H2(ν 2 = 0, j 2) collisions from initial levels of j 1 = 2–31 (j 2 = 0 or 1) to all lower rotational levels are presented. We carried out extensive quantum mechanical close-coupling calculations based on a recently published H2–H2 potential energy surface (PES) developed by Patkowski et al. that has been demonstrated to be more reliable than previous work. Rotational transition cross sections with initial levels of j 1 = 2–14, 18, 19, 24, and 25 were computed for energies ranging from 10−6 …

Oxidation Of Benzylic Alcohols And Lignin Model Compounds With Layered Double Hydroxide Catalysts, Justin K. Mobley, John A. Jennings, Tonya Morgan, Axel Kiefer, Mark Crocker

Chemistry Faculty Publications

Alcohol oxidation to carbonyl compounds is one of the most commonly used reactions in synthetic chemistry. Herein, we report the use of base metal layered double hydroxide (LDH) catalysts for the oxidation of benzylic alcohols in polar solvents. These catalysts are ideal reagents for alcohol oxidations due to their ease of synthesis, tunability, and ease of separation from the reaction medium. LDHs synthesized in this study were fully characterized by means of X-ray diffraction, NH₃-temperature programmed desorption (TPD), pulsed CO₂ chemisorption, N₂ physisorption, electron microscopy, and elemental analysis. LDHs were found to effectively oxidize benzylic alcohols …

Ultrafast And Nonlinear Spectroscopy Of Nanomaterials, Rami Anthony Khoury

LSU Doctoral Dissertations

Ultrafast and nonlinear spectroscopies are implemented in the investigation of excited-state dynamics and structural properties of materials and nanomaterials. In the first study, the excited-state dynamics of size-dependent colloidal TiO₂-Au nanocomposites are investigated using ultrafast transient absorption spectroscopy. The dynamics corresponding to the plasmon depletion band are characterized by electron-phonon and phonon-phonon coupling lifetimes that are observed to be independent of the gold nanocluster shell thickness. The excited-state dynamics corresponding to the interband transition of gold is also spectrally overlapped with the interfacial electron transfer lifetime, which is shown to decrease as the nanocluster shell thickness increases. In …

The Effects Of Cold Plasma Treatment On Sweet Basil (Ocimum Basilicum), Sauvelson Auguste

Seton Hall University Dissertations and Theses (ETDs)

The study discussed herein looks both to continue and to expand upon previous work conducted here at Seton Hall University, which investigated the effect of cold plasma processing on sweet basil and their essential oils. It was found that the application of cold plasma treatment increases plant growth and eugenol concentration, which is an essential oil component and one of the potential natural antioxidants used in food preservation. In this study, we considered methods for increasing the production and harvesting of plants that produce essential oils such as sweet basil (Ocimum basilicum). The study also incorporated more controls …

Semisynthesis Of A Mellein-Type 3,4-Dihydroisocoumarin From Cashew Nut Shell Liquid (Cnsl), Clarence A. Mgina, Fatma Kadir

Tanzania Journal of Science

Mellein-type 3,4-dihydroisocoumarin 39 (i.e., 8-methoxy-3-tridecyl-3,4-dihydroisocoumarin or 8-methoxy-3-tridecylisochroman-1-one), and its precursors, namely, methyl 2-methoxy-6-pentadecylbenzoate (37), methyl 2-methoxy-6-pentadecanoylbenzoate (38) and (E)-methyl 2-methoxy-6-(pentadec-1-enyl)benzoate (19) were synthesized from anacardic acid (12) as a starting material obtained from Cashew Nut Shell Liquid (CNSL) in an overall yield of 78%. The transformation of 12 to 39 involved protection of the reactive phenolic and carboxylic acid groups of compound 12 through methylation followed by hydrogenation so as to saturate the mono-, di- and tri-unsaturated C15 chains of anacardic acid (12). Subsequent benzylic oxidation and reduction of the keto functional group with concomitant dehydration of the alcohol led …

Determination Of Toxic Diethylene Glycol In Toothpastes In Dar Es Salaam By High Performance Thin Layer Chromatography And Colorimetric Methods, John Andrew Marco Mahugija

Tanzania Journal of Science

The aim of this study was to determine the presence and the levels of diethylene glycol (DEG) in toothpaste products commonly used in Dar es Salaam. Forty five samples of different brands of imported and locally manufactured toothpastes were collected and processed prior to analysis. High performance thin layer chromatography (HPTLC) method was used for the qualitative detection of diethylene glycol in the toothpastes. In quantitative analysis, a colorimetric method that involved ultraviolet–visible (UV-Vis) spectrophotometric measurements of absorbances of prepared coloured samples and standards was used. DEG was found in 37.8% of the tested samples. The concentrations of the DEG …

Cost Effective Strategy For The Synthesis Of Azo Dyes By Using Cashew Nut Shell Liquid (Cnsl), Mathias Yohana, Monica M. Ndoile, Quintino A. Mgani

Tanzania Journal of Science

The synthesis and dyeing properties of two types of azo dyes are reported in this paper. The two types of dyes were obtained from coupling of amino cardanol with unsaturated anacardic acid [ACUSA (Aminocardanol unsaturated anacardic acid)] and saturated anacardic acid [ACSA (Aminocardanol saturated anacardic acid)] separately. Both, anacardic acid and aminocardanol were obtained from CNSL as their source material. ACSA dyes were solid and dark brown while ACUSA were gelatinous and dark red. The performance of both ACUSA and ACSA dyes was moderate on textile fabrics with varying cotton content. The dyeing efficiency of the ACUSA was better than …

Effect Of Molten Salt Synthesis Processing Duration On The Photo- And Radioluminescence Of Uv- Visible- And X-Ray-Excitable La 2 Hf 2 O 7 :Eu 3+ Nanoparticles, Jose P. Zuniga, Santosh K. Gupta, Maya Abdou, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Ln 3+ -ion-doped nanomaterials possess excellent properties because of their high color purity, longer excited state lifetime, narrow emission, and large Stokes shifts. In this work, we studied the correlation between the luminescence properties of La 2 Hf 2 O 7 :Eu 3+ pyrochlore nanoparticles (NPs) synthesized by a molten salt synthesis (MSS) method at a relatively low temperature and several MSS processing durations (from 1 to 12 h). We synthesized these NPs with different sizes just by changing the MSS processing time without subjecting to high temperature. Raman spectroscopy confirmed the stabilization of the ideal pyrochlore structure of the …

New Insights Into The Design Of Conjugated Polymers For Intramolecular Singlet Fission, Jiahua Hu, Ke Xu, Lei Shen, Qin Wu, Guiying He, Jie-Yu Wang, Jian Pei, Jianlong Xia, Matthew Y. Sfeir

Publications and Research

Singlet fission (SF), a multiple exciton generation process that generates two triplet excitons after the absorption of one photon, can potentially enable more efficient solar cell designs by harvesting energy normally lost as heat. While low-bandgap conjugated polymers are highly promising candidates for efficient SF-based solar cells, few polymer materials capable of SF have been reported because the SF process in polymer chains is poorly understood. Using transient spectroscopy, we demonstrate a new, highly efficient (triplet yield of 160-200%) isoindigo-based donor–acceptor polymer and show that the triplet pairs are directly emissive and exhibit a time-dependent energy evolution. Importantly, aggregation in …

Nickel Exposure Reduces Enterobactin Production In Escherichia Coli, Clorissa L. Washington-Hughes, Geoffrey T. Ford, Alsten D. Jones, Kimberly Mcrae, Franklin Wayne Outten

Faculty Publications

Escherichia coli is a well- studied bacterium that can be found in many niches, such as industrial wastewater, where the concentration of nickel can rise to low- millimolar levels. Recent studies show that nickel exposure can repress pyochelin or induce pyo-verdine siderophore production in Pseudomonas aueroginosa. Understanding the mo-lecular cross- talk between siderophore production, metal homeostasis, and metal toxicity in microorganisms is critical for designing bioremediation strategies for metal- contaminated sites. Here, we show that high- nickel exposure prolongs lag phase duration as a result of low- intracellular iron levels in E. coli. Although E. coli cells respond to low- …

Nickel Exposure Reduces Enterobactin Production In Escherichia Coli, Clorissa L. Washington – Hughes, Geoffrey T. Ford, Alsten D. Jones, Kimberly Mcrae, Franklin W. Outten

Faculty Publications

Escherichia coli is a well- studied bacterium that can be found in many niches, such as industrial wastewater, where the concentration of nickel can rise to low- millimolar levels. Recent studies show that nickel exposure can repress pyochelin or induce pyo-verdine siderophore production in Pseudomonas aueroginosa. Understanding the mo-lecular cross- talk between siderophore production, metal homeostasis, and metal toxicity in microorganisms is critical for designing bioremediation strategies for metal- contaminated sites. Here, we show that high- nickel exposure prolongs lag phase duration as a result of low- intracellular iron levels in E. coli. Although E. coli cells respond to low- …

Spreading Electron Density Thin: Increasing The Chromophore Size In Polyaromatic Wires Decreases Interchromophoric Electronic Coupling, Mohammad Mosharraf Hossain, Maxim Vadimovich Ivanov, Denan Wang, Scott A. Reid, Rajendra Rathore

Chemistry Faculty Research and Publications

The development of novel polychromophoric materials using extended polycyclic aromatic hydrocarbons as a single large chromophore holds promise for long-range charge-transfer applications in photovoltaic devices and molecular electronics. However, it is not well-understood how the interchromophoric electronic coupling varies with the chromophore size in linearly connected molecular wires. Here, we show with the aid of electrochemistry, electronic spectroscopy, density functional theory calculations, and theoretical modeling that as the number of aromatic moieties in a single chromophore increases, the interchromophoric electronic coupling decreases and may reach negligible values if the chromophore is sufficiently large. The origin of this initially surprising result …

Hiv-1 Integrase-Targeted Short Peptides Derived From A Viral Protein R Sequence, Xue Zhi Zhao, Mathieu Métifiot, Evgeny Kiselev, Jacques Kessl, Kasthuraiah Maddali, Christophe Marchand, Mamuka Kvaratskhelia, Yves Pommier, Terrence R. Burke Jr.

Faculty Publications

HIV-1 integrase (IN) inhibitors represent a new class of highly effective anti-AIDS therapeutics. Current FDA-approved IN strand transfer inhibitors (INSTIs) share a common mechanism of action that involves chelation of catalytic divalent metal ions. However, the emergence of IN mutants having reduced sensitivity to these inhibitors underlies efforts to derive agents that antagonize IN function by alternate mechanisms. Integrase along with the 96-residue multifunctional accessory protein, viral protein R (Vpr), are both components of the HIV-1 pre-integration complex (PIC). Coordinated interactions within the PIC are important for viral replication. Herein, we report a 7-mer peptide based on the shortened Vpr …

Removal Of Acid Yellow 25 From Aqueous Solution By Chitin Prepared From Waste Snow Crab Legs, Chin-Chuan Wei, Inoka K. Pathiraja, Emily Fabry, Kyle Schafer, Nick Schimp, Tuo-Ping Hu, Lawrence P. Norcio

SIUE Faculty Research, Scholarship, and Creative Activity

Acid Yellow 25 (AY25) is used in the textile industry for dyeing of natural and synthetic fibers, and is also used as a coloring agent in paints, inks, plastics, and leathers. Effluents from such industries are major sources of water pollution. Hence, it is important to find simple, efficient, and inexpensive ways to remove these dyes from wastewater. Here, we determined the suitability of chitin extracted from waste crab legs as an adsorbent for removing AY25 dye. The adsorption kinetics was modeled using pseudo-first order, pseudo-second order, and intraparticle diffusion equations to determine the rate controlling step. Results showed that …

Unraveling Substituent Effects On The Glass Transition Temperatures Of Biorenewable Polyesters, Xiaopeng Yu, Junteng Jia, Shu Xu, Ka Un Lao, Maria J. Sanford, Ramesh K. Ramakrishnan, Sergei I. Nazarenko, Thomas R. Hoye, Geoffrey W. Coates, Robert A. Distasio Jr.

Faculty Publications

Converting biomass-based feedstocks into polymers not only reduces our reliance on fossil fuels, but also furnishes multiple opportunities to design biorenewable polymers with targeted properties and functionalities. Here we report a series of high glass transition temperature (T_g up to 184 °C) polyesters derived from sugar-based furan derivatives as well as a joint experimental and theoretical study of substituent effects on their thermal properties. Surprisingly, we find that polymers with moderate steric hindrance exhibit the highest T_g values. Through a detailed Ramachandran-type analysis of the rotational flexibility of the polymer backbone, we find that additional steric hindrance does …

Germania-Based Sol-Gel Coatings And Core-Shell Particles In Chromatographic Separations, Chengliang Jiang

USF Tampa Graduate Theses and Dissertations

Chapter one reviewed the development of sol-gel stationary phase for gas chromatograph (GC). Inorganic sol-gel precursor creates the substrate support for stationary phase bind to silica surface through the condensation of silanol groups, the rough surface with enhanced surface area enlarger the capacity of the sol-gel stationary phase, the porosity of sol-gel structure decreases the mass transferring coefficient, the term C in Van Deemter equation, which makes sol-gel stationary phase thicker coating up to 1 um but keeps the high resolution for gas chromatography. Chemical bound stationary phase significantly improve GC column with better thermal stability and solvent stability. Partial …

59th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 59th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Snowbird, Utah, July 22-27, 2018.

The Commutator Of The Runge Lenz Vector With Other Operators Of The H-Atoms Physics Using Maxima, Carl W. David

Chemistry Education Materials

Commutators of components of the Runge-Lenz vector and constants of the motion and ladder operators for the H-atom problem are evaluated using brute force calculus and Maxima.

Applications Of Click Chemistry In The Development Of Hiv Protease Inhibitors, Mukesh Madan Mudgal, Nagaraju Birudukota, Mayur A. Doke

Chemistry and Physics Faculty Articles

Acquired Immunodeficiency Syndrome (AIDS) has been devastating for millions of people around the world. Inhibition of the human immunodeficiency virus (HIV) protease is among the most important approaches for the therapeutic intervention in HIV infection. Since the discovery of the HIV-1 protease, this enzyme has been considered as a key target for the inhibition of viral replication. A large body of research has been done to develop an effective HIV-1 protease inhibitor. There are to date 10 HIV-1 protease inhibitor drugs approved by the Food and Drug Administration (FDA) that have improved the survival and quality of life of HIV …

Pressure‐Tuneable Visible‐Range Band Gap In The Ionic Spinel Tin Nitride, John S. C. Kearney, Miglė Graužinytė, Dean Smith, Daniel Sneed, Christian Childs, Jasmine Hinton, Changyong Park, Jesse S. Smith, Eunja Kim, Samuel D. S. Fitch, Andrew L. Hector, Chris J. Pickard, José A, Flores-Livas, Ashkan Salamat

Physics & Astronomy Faculty Research

The application of pressure allows systematic tuning of the charge density of a material cleanly, that is, without changes to the chemical composition via dopants, and exploratory high‐pressure experiments can inform the design of bulk syntheses of materials that benefit from their properties under compression. The electronic and structural response of semiconducting tin nitride Sn3N4 under compression is now reported. A continuous opening of the optical band gap was observed from 1.3 eV to 3.0 eV over a range of 100 GPa, a 540 nm blue‐shift spanning the entire visible spectrum. The pressure‐mediated band gap opening is general to this …

Developing More Specific Mirna Biogenesis Inhibitors To Get Effective Regulation Of Mirnas, Umesh Bhattarai

Chemistry and Chemical Biology ETDs

MicroRNAs (miRNAs) are short (~ 22 nucleotides long) noncoding RNAs that regulate gene expression post-transcriptionally. They control the expression of various genes that are crucial for cellular function, development and human diseases. Tools to regulate the level and function of miRNAs facilitate the studies of their functions and have therapeutic applications. In my thesis, I developed a newly customizable miRNA biogenesis inhibitor to regulate miRNAs.

Antisense oligonucleotides (ASOs) have been used to regulate miRNA through controlling their production or function. Although commonly used due to the fact that they are easy to design, several limitations exist for ASOs including serious …

Nanostructured Fibers As A Versatile Photonic Platform: Radiative Cooling And Waveguiding Through Transverse Anderson Localization, Norman Nan Shi, Cheng-Chia Tsai, Michael J. Carter, Jyotirmoy Mandal, Adam C. Overvig, Matthew Y. Sfeir, Ming Lu, Catherine L. Craig, Gary D. Bernard, Yuan Yang, Nanfang Yu

Publications and Research

Broadband high reflectance in nature is often the result of randomly, three-dimensionally structured materials. This study explores unique optical properties associated with one-dimensional nanostructures discovered in silk cocoon fibers of the comet moth, Argema mittrei. The fibers are populated with a high density of air voids randomly distributed across the fiber cross-section but are invariant along the fiber. These filamentary air voids strongly scatter light in the solar spectrum. A single silk fiber measuring ~50 μm thick can reflect 66% of incoming solar radiation, and this, together with the fibers' high emissivity of 0.88 in the mid-infrared range, allows …

Controlled Polymerization Of Ethyl Glyoxylate Using Alkyllithium And Alkoxide Initiators, Amir Rabiee Kenaree, Elizabeth R. Gillies

Chemistry Publications

The synthesis of poly(ethyl glyoxylate)s (PEtGs) by anionic polymerization was explored. PEtGs are a subclass of stimuli-responsive self-immolative polymers with promising properties for applications as coatings, sensors, and drug delivery vehicles. In this report, a new purification procedure for the preparation of highly pure ethyl glyoxylate (EtG), suitable for anionic polymerization reactions, and the first successful examples of controlled polymerization of EtG are described. n-BuLi, PhLi, and t-BuLi were employed as initiators under different experimental conditions and their behavior was examined using NMR spectroscopy, size exclusion chromatography, and thermal analysis to develop an optimized procedure. As functional alkoxide …

Spectroscopy And Formation Of Lanthanum-Hydrocarbon Radicals Formed By C—H And C—C Bond Activation Of 1-Pentene And 2-Pentene, Wenjin Cao, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang

Chemistry Faculty Publications

La atom reactions with 1-pentene and 2-pentene are carried out in a laser-vaporization molecular beam source. The two reactions yield the same metal-hydrocarbon products from the dehydrogenation and carbon–carbon bond cleavage of the pentene molecules. The dehydrogenated species La(C₅H₈) is the major product, whereas the carbon–carbon bond cleaved species La(C₂H₂) and La(C₃H₄) are the minor ones. La(C₁₀H₁₈) is also observed and is presumably formed by La(C₅H₈) addition to a second pentene molecule. La(C₅H₈) and La(C_{2 …}

How To Run Molecular Dynamics Simulations On Electrospray Droplets And Gas Phase Proteins: Basic Guidelines And Selected Applications., Lars Konermann, Haidy Metwally, Robert G Mcallister, Vlad Popa

Chemistry Publications

The ability to transfer intact proteins and protein complexes into the gas phase by electrospray ionization (ESI) has opened up numerous mass spectrometry (MS)-based avenues for exploring biomolecular structure and function. However, many details regarding the ESI process and the properties of gaseous analyte ions are difficult to decipher when relying solely on experimental data. Molecular dynamics (MD) simulations can provide additional insights into the behavior of ESI droplets and protein ions. This review is geared primarily towards experimentalists who wish to adopt MD simulations as a complementary research tool. We touch on basic points such as force fields, the …

Identification Of Coliphages In The Aviary At Brookgreen Gardens And The Factors That Might Influence Coliphage Population Dynamics In This Cypress Swamp Environment, Olivia Shirley, Lisa Pieterse, Paul E. Richardson

Journal of the South Carolina Academy of Science

It has been understood that the presence of coliphages (bacteriophages specific for E. coli) in water is an indirect measurement of fecal contamination. Bacteriophages have been suggested to hold an important role in regulating the bacterial population. This pilot study analyzes the relationship between the presence of coliphages in the water in the aviary at Brookgreen Gardens and how environmental factors such as temperature, pH, and turbidity affect the presence of these viruses over the time period of three months (June 2017 through August 2017). Coliphages found in volary water sources were speculated to be deposited directly by birds that …