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Functionalized Cationic [4]Helicenes With Unique Tuning Of Absorption, Fluorescence And Chiroptical Properties Up To The Far-Red Range, I. Hernández Delgado, S. Pascal, A. Wallabregue, R. Duwald, C. Besnard, L. Guénée, C. Nançoz, E. Vauthey, R. Tovar, J. Lunkley, Gilles Muller, J. Lacour

Faculty Publications, Chemistry

Unprecedented regioselective post-functionalization of racemic and enantiopure cationic diaza [4]helicenes is afforded. The peripheral auxochrome substituents allow a general tuning of the electrochemical, photophysical and chiroptical properties of the helical dyes (26 examples). For instance, electronic absorption and circular dichroism are modulated from the orange to near-infrared spectral range (575–750 nm), fluorescence quantum efficiency is enhanced up to 0.55 (631 nm) and circularly polarized luminescence is recorded in the red (|glum| ∼ 10−3).

Towards Structural Determination Of Human Α1-Glycine Receptor Allostery, Rathna Jyothi Veeramachaneni

Electronic Theses and Dissertations

Recent advances in technology have led to the determination of numerous notable structures of membrane proteins. While they provide valuable information about the structure of membrane proteins these studies often provide static images with potentially limited dynamics, and structural determination often requires truncation of flexible regions, and often utilizes bacterial homologs given the need for stable, heterologous overexpression. In order to better understand allostery at a molecular level, state-dependent crosslinking studies coupled with multidimensional mass spectrometry (MS) were conducted on glycine receptor (GlyR) stabilized in different allosteric states. Predominant allosteric states were stabilized using wild type or mutated receptor in …

Determination Of Hexavalent Chromium (Cr(Vi)) Concentrations Via Ion Chromatography And Uv-Vis Spectrophotometry In Samples Collected From Nacogdoches Wastewater Treatment Plant, East Texas (Usa), Kefa Karimu Onchoke, Salomey A. Sasu

Faculty Publications

The concentration of hexavalent chromium (Cr(VI)), a toxic environmental pollutant and carcinogen, was determined in samples collected from Nacogdoches Wastewater Treatment Plant (NWWTP) using ion chromatography and UV-visible spectrophotometry (IC, UV-Vis). On reaction with 1,5-diphenylcarbazide (DPC) Cr+6 forms a 1,5-diphenylcarbazide-Cr(VI) complex, which is then analyzed at 530nm and 540nm, respectively. Via ion chromatography Cr(VI) concentrations were in the range of 0.00190 ± 0.0020 and 0.0010 ± 0.0006ppm at the influent and effluent, respectively. With the use of standard addition wastewater samples were spiked with a 0.5ppm Cr(VI) standard of various amounts and subsequently analyzed with UV-Vis spectrophotometry. The spiked concentrations …

Water Soluble Cationic Porphyrin Sensor For Detection Of Hg2+, Pb2+, Cd2+, And Cu2+, Matibur Zamadar, Christopher Orr, Miranda Uherek

Faculty Publications

Here we report the sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (1) for simultaneous detection of toxic metal ions by using UV-vis spectroscopy. Cationic porphyrin 1 displayed different electronic absorptions in UV-vis region upon interacting with Hg2+, Pb2+, Cd2+, and Cu2+ ions in neutral water solution at room temperature. Quite interestingly, the porphyrin 1 showed that it can function as a single optical chemical sensor and/or metal ion receptor capable of detecting two or more toxic metal ions, particularly Hg2+, Pb2+, and Cd2+ ions coexisting in a water sample. Porphyrin 1 in an aqueous solution provides a unique …

"High-Valent Copper In Biomimetic And Biological Oxidations", J. Brannon Gary

Faculty Publications

A long-standing debate in the Cu-O2 field has revolved around the relevance of the Cu(III) oxidation state in biological redox processes. The proposal of Cu(III) in biology is generally challenged as no spectroscopic or structural evidence exists currently for its presence. The reaction of synthetic Cu(I) complexes with O2 at low temperature in aprotic solvents provides the opportunity to investigate and define the chemical landscape of Cu-O2 species at a small molecule level of detail; eight different types are characterized structurally, three of which contain at least one Cu(III) center. Simple imidazole or histamine ligands are competent in these oxygenation …

Bioavailability And Transformation Of Silver Nanoparticles In The Freshwater Environment, Seth W. Brittle

Browse all Theses and Dissertations

The proliferation of silver nanoparticles (AgNPs) in consumer products and industrial applications has generated many environmental concerns since the chemistry of silver changes at the nanoscale and the very properties that make them desirable – their unique reactivity – may pose environmental risks. This dissertation addresses these concerns from three different angles. First, freshwater crayfish is demonstrated as a potential benthic indicator of Ag pollution since Ag accumulation depends on the form of Ag. The uptake and distribution of Ag (from AgNPs or Ag+) in tissue samples were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The hepatopancreas (1.5-17.4 …

Properties And Drug-Likeness Of Compounds That Inhibit Ebola Virus Disease (Evd), Ronald Bartzatt

Chemistry Faculty Publications

Aims: To present the molecular structures of compounds that has been shown to inhibit the proliferation of Ebola virus. To elucidate the molecular properties of these virus inhibiting compounds.

Study Design: The molecular properties of virus inhibiting compounds are elucidated and compiled. Pattern recognition methods and statistical analysis are applied to determine optimal properties of this group of compounds.

Place and Duration of Study: Chemistry Department, Durham Science Center, University of Nebraska, Omaha NE. between December 2015 and February 2016.

Methodology: A total of 60 compounds were identified as inhibiting the virus Ebola. The molecular properties such as Log P, …

Novel Photodynamic Cancer Therapy Agent And Biochemical Phosphate Sensor Based On Nanomaterials, Alaa Fadhel

Electronic Theses and Dissertations

Biochemical research and clinical studies have revolutionized the field of medicine in both diagnosis and therapy. Researchers in the field of biochemistry and biotechnology are using nanomaterials in different applications to develop devices and materials that offer benefits to both patients and the health care industry. These include biochemical sensors, enzyme encapsulation, biomarkers, and drug delivery improvements for the treatment of cancer. This dissertation focuses on investigating two biochemical aspects using nanomaterials; namely therapy and clinical diagnosis. For therapy purposes, Silica nanoparticles were used as drug delivery system to develop a new photodynamic cancer therapy agent photo-acid generator (PAG) that …

Photoassisted Generation Of Complex N, O, S Polyheterocycles, Weston James Umstead

Electronic Theses and Dissertations

This research set out to continue the exploration and diversification of excited state o-azaxylylene cycloadditions, utilizing both pre-photochemical and post-photochemical modifications.

Pre-photochemical modifications came through the addition of heteroatoms, namely nitrogen and oxygen, to the tether that links the unsaturated photopendant to the photogenerated o-azaxylylene. Photochemistry resulted in the formation of new, interesting N, O, S polyheterocycles.

Post-photochemical modifications took place through several different cycloaddition reactions, including a [4+2] hetero-Diels Alder reaction, a [4+2] Povarov cyclization, a [3+2] nitrile oxide addition, and a [3+2] nitrone cyclization. These reactions were applied first to a model system, and then to …

Ring Closures And The Hammond Postulate, Charles A. Kingsbury

Department of Chemistry: Faculty Publications

This work reports an investigation of ring closure processes in relation to the Hammond postulate. Calculations favor the importance of thermodynamics, not kinetics, as the basis for the Hammond postulate. A kinetically rapid, but thermodynamically unfavorable reaction is shown to resemble product. The ease of ring closure to three-membered rings, compared to four-membered rings, is thought to be associated with conformational mobility and perhaps vibrations coupled to the reaction coordinate motion in the case of four-membered rings.

Agricultural Fires In The Southeastern U.S. During Seac4Rs: Emissions Of Trace Gases And Particles And Evolution Of Ozone, Reactive Nitrogen, And Organic Aerosol, Xiaoxi Liu, Y. Zhang, L. G. Huey, R. J. Yokelson, Y. Wang, J. L. Jimenez, P. Campuzano-Jost, A. J. Beyersdorf, D. R. Blake, Y. Choi, J. M. St. Clair, J. D. Crounse, D. A. Day, G. S. Diskin, A. Ried, S. R. Hall, T. F. Hanisco, L. E. King, S. Meinardi, T. Mikoviny, B. B. Palm, J. Peischl, A. E. Perring, I. B. Pollack, T. B. Ryerson, G. Sachse, J. P. Schwarz, I. J. Simpson, D. J. Tanner, K. L. Thornhil, K. Ullmann, R. J. Weber, P. O. Wennberg

Chemistry and Biochemistry Faculty Publications

Emissions from 15 agricultural fires in the southeastern U.S. were measured from the NASA DC-8 research aircraft during the summer 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign. This study reports a detailed set of emission factors (EFs) for 25 trace gases and 6 fine particle species. The chemical evolution of the primary emissions in seven plumes was examined in detail for ~1.2 h. A Lagrangian plume cross-section model was used to simulate the evolution of ozone (O3), reactive nitrogen species, and organic aerosol (OA). Observed EFs are generally consistent with previous …

Planning, Implementation, And Scientific Goals Of The Studies Of Emissions And Atmospheric Composition, Clouds And Climate Coupling By Regional Surveys (Seac4Rs) Field Mission, Owen B. Toon, Hal Maring, Jack Dibb, Richard Ferrare, Daniel J. Jacob, Eric J. Jensen, Z. Johnny Luo, Gerald G. Mace, Laura L. Pan, Lenny Pfister, Karen H. Rosenlof, Jens Redemann, Jeffrey S. Reid, Hanwant B. Singh, Anne M. Thompson, Robert Yokelson, Patrick Minnis, Gao Chen, Kenneth W. Jucks, Alex Pszenny

Chemistry and Biochemistry Faculty Publications

The Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) fieldmission based at Ellington Field, Texas, during August and September 2013 employed the most comprehensive airborne payload to date to investigate atmospheric composition over North America. The NASA ER-2, DC-8, and SPEC Inc. Learjet flew 57 science flights fromthe surface to 20 km. The ER-2 employed seven remote sensing instruments as a satellite surrogate and eight in situ instruments. The DC-8 employed 23 in situ and five remote sensing instruments for radiation, chemistry, and microphysics. The Learjet used 11 instruments to explore cloud microphysics. SEAC4RS …

Ice-Nucleating Particle Emissions From Biomass Combustion And The Potential Importance Of Soot Aerosol, E. J.T. Levin, G. R. Mcmeeking, P. J. Demott, C. S. Mccluskey, C. M. Carrico, S. Nakao, T. Jayarathne, E. A. Stone, C. E. Stockwell, R. J. Yokelson, S. M. Kreidenweis

Chemistry and Biochemistry Faculty Publications

Ice-nucleating particles (INPs) are required for initial ice crystal formation in clouds at temperatures warmer than about -36°C and thus play a crucial role in cloud and precipitation formation. Biomass burning has been found to be a source of INPs in previous studies and is also a major contributor to atmospheric black carbon (BC) concentrations. This study focuses on isolating the BC contribution to the INP population associated with biomass combustion. Emissions of condensation mode INPs from a number of globally relevant biomass fuels were measured at -30°C and above water saturation as fires progressed from ignition to extinguishment in …

Rapidly Evolving Ultrafine And Fine Mode Biomass Smoke Physical Properties: Comparing Laboratory And Field Results, Christian M. Carrico, Anthony J. Prenni, Sonia M. Kreidenweis, Ezra J.T. Levin, Christina S. Mccluskey, Paul J. Demott, Gavin R. Mcmeeking, Shunsuke Nakao, Chelsea Stockwell, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

Combining field and laboratory results, we present biomass smoke physical properties. We report sub-0.56 µm diameter (Dp) particle sizing (fast mobility particle sizer, FMPS) plus light absorption and scattering at 870nm (photoacoustic extinctiometer). For Dp<200 >nm, the FMPS characterized sizing within ±20% compared to standards. As compared to the traditional scanning mobility particle sizer, the FMPS responded most accurately to single-mode polydispersions with mean Dp<200 >nm, which characterized the smoke sampled here. Smoke was measured from laboratory fresh emissions (seconds to hours old), the High Park Fire (hours to<1 >day), and from regional biomass burning (several days). During a High …

The Periodical Winter 2016, Southern Adventist University

the Periodical – Chemistry Department Newsletter

Volume 3, issue 2 of the Periodical includes articles about the Chemistry Club's community service, a pictorial listing of May 2016 graduates, student Jeron Estwick's presentation at a chemistry conference, a feature on students recognized for academic achievement, and an alumni spotlight.

Modified Electrodes With Grafted Dna And Oligonucleotides For Detection And Quantification Of Peroxynitrate, Heba Azmy Salim

ETD Archive

Peroxynitrite (ONOO-) is a strong oxidizing and nitrating agent, and its formation has been correlated with many pathological conditions. It is generated in-vivo through the diffusion-controlled reaction between nitric oxide and superoxide. Peroxynitrite has been linked to nitration of protein and DNA as well as to DNA strand breaks. Accumulation of mutations and/or other kinds of DNA damage represent a carcinogenic risk. The accurate measurement of peroxynitrite concentration has been a challenge since this analyte is very unstable and reacts with many cellular targets. Development of analytical techniques capable of rapid and sensitive detection of this fast-reacting and damaging agent …

Profiling Cell Surface Sialylation And Desialylation Dynamics Of Immune Cells, Dan Wang

ETD Archive

Sialic acids (SAs) are a diverse family of naturally occurring 2-keto-3-deoxy-nononic acids that are involved in a wide range of biological processes, including early fetal development, cellular recognition, and utilization by microbes. While it is clear that cell surface SAs are highly involved in the immune system, the sialylation status of individual immune cells and functions are still unknown. In this study, I combined the newly developed LC-MS/MS methods with flow cytometry and confocal microscopy to systematically study the sialylation and desialylation dynamics of macrophages at different conditions.

First, I developed an accurate LC-MS/MS method to quantify free SA in …

The Role Of Rnase L In Type I Diabetes And Development Of Quantitative Lc-Ms/Ms Methods For The Pharmacological Studies Of Anti-Cancer Drug Candidates, Chun Zeng

ETD Archive

PROJECT I: The cause of type I diabetes continues to be a focus of investigation. In this study, we found that 2-5A dependent RNase L (RNase L), an IFN-a-inducible enzyme that functions in IFN action against viruses and cell proliferation, played an important role in dsRNA-induced onset of type I diabetes. By using RNase L deficient RIP-B7.1 mice which are more vulnerable to environmental harmful factors such as viral infection, we demonstrated that deficiency of RNase L in mice resulted in a significant delay of diabetes onset induced by polyinosinic:polycytidylic acid (poly I:C), a type of dsRNA, and streptozotocin (STZ). …

Studying The Atp Cosubstrate Promiscuity Of Nucleotide And Lipid Kinases, Thilani Murium Anthony

Wayne State University Dissertations

The kinase family consist of a large assortment of enzymes that phosphorylate a variety of substrates, including proteins, nucleosides, polynucleotides, lipids, sugars, and other small molecules. The Pflum lab recently found that protein kinases promiscuously accept an ATP analog containing a biotin at the γ-phosphate (ATP-biotin) as a cosubstrate to label the hydroxyl side chains of Ser, Thr and Tyr residues with biotin. The main goal of this new project is to extend the use of kinase-catalyzed biotinylation towards polynucleotides. Crystallographic studies of T4 polynucleotide kinase (T4 PNK) that phosphorylates the 5’-hydroxyl termini of DNA and RNA show a solvent …

Synthesis Of Dinucleating Ligands And Their Dinuclear Metal Complxes:Applications In Sensing And Small Molecule Activation, Jeffrey William Beattie

Wayne State University Dissertations

Dinuclear metal complexes provide a route to interesting structure and reactivity. Two common uses of dinuclear metal complexes are sensing and activation of small molecules. Herein we describe a series of dinuclear metal complexes capable of sensing of oxalate and activation of carbon disulfide.

Sensing of oxalate is of great interest because high oxalate concentration (hypooxaluria) is a major cause of kidney stones. Dinuclear metal complexes can act as sensors for oxalate because the oxalate can bridge between the metal centers. Herein we describe a colorimetric oxalate sensor capable of regeneration. Upon addition of oxalate to a pink solution of …

Development Of Gamma-Modified Atp Analogs To Study Kinase-Catalyzed Phosphorylations, Ahmed Eid Fouda

Wayne State University Dissertations

Kinase-catalyzed protein phosphorylation is one of the most important post-translational modifications that controls cascades of biochemical reactions. Irregularities in phosphorylation result in many diseases, such as diabetes mellitus, Parkinsons, and cancer. The development of new methods to monitor kinase-catalyzed phosphorylation is needed to decipher details of normal and diseased cell signaling. The Pflum lab recently developed several -modified ATP analogs to study kinase catalyzed phosphorylation reactions. The -modified ATP analogs have different tags, such as biotin for substrate labeling or aryl-azide for kinase substrates identification. Unfortunately, use of -modified ATP analogs was limited to in vitro studies due to the …

Synthesis Of Apramycin And Paromomycin Derivatives As Potential Next Generation Aminoglycoside Antibiotics And Chemistry Of Isothiocyanato Sialyl Donors, Appi Reddy Mandhapati

Wayne State University Dissertations

AGAs are clinically important antibacterials for human therapy and have long been used as highly potent antibiotics for treating several bacterial infections. The fidelity of protein synthesis is affected by AGAs in the course of binding to specific sites of the bacterial rRNA. The clinical use of AGAs and their applications as therapeutics is restricted by toxicity (irreversible ototoxicity and reversible nephrotoxicity) and by the resistance of pathogens. The objective of this research was the development of proficient AGAs that are less toxic (i.e., more selective) and that evade resistance. The first three chapters of this thesis are aimed towards …

Novel Approaches For Assessment Of Copper Toxicity: Fast Scan Cyclic Voltammetry And Optical Bioassays, Annette R. Tremonti

Wayne State University Dissertations

Anthropogenic activities negatively impact fresh water ecosystems through toxic contaminants that are released into the environment. Copper (Cu) is a water contaminant that is fundamentally persistent once introduced into the environment that has the potential for bioaccumulation. Although Cu toxicity has been studied for decades, there is still a continuing problem with new sources and pathways. New approaches are needed to understand distribution and transport of Cu and its potential for complex biological impacts beyond the simple assessment of lethality. Several novel approaches were used in this research project to advance our understanding of Cu toxicity, including fast scan cyclic …

A Novel, Ultra-Fast Electrochemical Tool To Study Speciation Of Trace Metals In Aqueous Solution, Pavithra Pathirathna

Wayne State University Dissertations

Trace metals play important roles in biological and ecological systems. In biology, trace metals act as catalytic or structural cofactors and regulate biochemical processes. In the environment, natural and anthropogenic sources of trace metals mobilized into natural waters where they can create harmful and persistent pollution. Trace metal chemistry in physiological and environmental systems can fluctuate rapidly which makes it difficult to clearly define trace metals’ roles in these systems with traditional analytical methods. Furthermore, these systems are often chemically harsh and physically delicate (e.g. the brain), factors that add to the challenge of analysis in real systems. Fast scan …

Live, Attenuated Vaccines And Methods Of Making And Using, Jiantao Guo, Qingsheng Li, Wei Niu, Yue Li, Nanxi Wang

Department of Chemistry: Faculty Publications

A live, attenuated HIV vaccine is provided, and methods of making a atenuated HIV vaccine are provided.

The Development Of Peptide Ligands To Target H69 Rrna, Danielle Nicole Dremann

Wayne State University Dissertations

ABSTRACT

THE DEVELOPMENT OF PEPTIDE LIGANDS TO TARGET H69

by

DANIELLE NICOLE DREMANN

December 2015

Advisor: Prof. Christine S. Chow

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

In the development of peptide ligands to target H69, SPPS and ESI MS was used to determine if 1) peptides could bind to modified H69 and 2) if increased affinity for the target RNA could be enhanced with modification. An alanine and arginine scan was synthesized and tested for this determination. Selected peptides were then tested using biophysical techniques such as circular dichroism and isothermal titration calorimetry. An assay was also designed to …

Nucleophile Promoted Gold Redox Catalysis With Diazonium Salts: C-Br, C-S And C-P Bond Formation Through Catalytic Sandmeyer Coupling, Haihui Peng, Rong Cai, Chang Xu, Hao Chen, Xiaodong Shi

Chemistry Faculty Publications

Gold-catalyzed C-heteroatom (C-X) coupling reactions are evaluated without using sacrificial oxidants. Vital to the success of this methodology is the nucleophile-assisted activation of aryldiazonium salts, which could be an effective oxidant for converting Au(i) to Au(iii) even without the addition of an assisting ligand or photocatalyst. By accelerating the reaction kinetics to outcompete C-C homo-coupling or diazonium dediazoniation, gold-catalyzed Sandmeyer reactions were achieved with different nucleophiles, forming C-Br, C-S and C-P bonds in high yields and selectivities.

Electron Transfer Studies In Langmuir-Blodgett Films Of Metallosurfactants For Current Rectification, Corrosion Mitigation, And Water Oxidation, Sunalee Gonawala Jayasundara Mudiyanselage

Wayne State University Dissertations

The work presented in this dissertation is focused on the design and synthesis of new redox-active amphiphilic architectures to optimize and understand the redox, electronic, and film formation properties for applications in current rectification, corrosion mitigation, and water oxidation. As such, new redox-active, and amphiphilic iron(III), cobalt(III), nickel(II), copper(II), and zinc(II) complexes were synthesized as precursors for Langmuir-Blodgett films used for the aforementioned applications.

For the use in molecular rectification, amphiphilic copper(II) and nickel(II) complexes with [N2O2] ligand environment were synthesized. Homogeneous film formation ability was observed between ~20-25 mN/m pressure, with a film collapse observed at ~35 mN/m for …

The Unusual Substrate Specificity Of A Virulence Associated Serine Hydrolase From The Highly Toxic Bacterium, Francisella Tularensis, Alexander M. Farberg, Whitney K. Hart, R. Jeremy Johnson

Scholarship and Professional Work - LAS

Francisella tularensis is the causative agent of the highly, infectious disease, tularemia. Amongst the genes identified as essential to the virulence of F. tularensis was the proposed serine hydrolase FTT0941c. Herein, we purified FTT0941c to homogeneity and then characterized the folded stability, enzymatic activity, and substrate specificity of FTT0941c. Based on phylogenetic analysis, FTT0941c was classified within a divergent Francisella subbranch of the bacterial hormone sensitive lipase (HSL) superfamily, but with the conserved sequence motifs of a bacterial serine hydrolase. FTT0941c showed broad hydrolase activity against diverse libraries of ester substrates, including significant hydrolytic activity across alkyl ester substrates from …

Surprising Impact Of Remote Groups On The Folding–Unfolding And Dimer-Chain Equilibria Of Bifunctional H-Bonding Unimers, Rui Liu, Shuang Cheng, Erin S. Baker, Richard D. Smith, Xiao Cheng Zeng, Rui Liu

Xiao Cheng Zeng Publications

Oligoamide 1, consisting of two H-bonding units linked by a trimethylene linker, was previously found to form a very stable, folded dimer. In this work, replacing the side chains and end groups of 1 led to derivatives that show the surprising impact of end groups on the folding and dimer-chain equilibria of the resultant molecules.