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Towards The Synthesis Of Magnesidin, Subramanya Pingali

LSU New Orleans Theses and Dissertations

Magnesidin is a magnesium chelate of the 3-hexanoyl and 3-octanoyl tetramic acid derivatives isolated from Psuedomonas magensiorubra. Its activity against grampositive bacteria was found to be a specific target for Gingivitis, a dental plaque.Although the synthesis of magnesidin has been reported earlier, it was not reproducible. The highly polar nature and it’s ability to exhibit tautomerization makes their chemical behavior complex and difficult to predict its structure. A variety of reactions and an in depth understanding of the chemical structure is necessary to attain the synthesis of these compounds. This dissertation focuses on addressing the attempts towards the synthesis …

Ferritin Diversity: Mechanistic Studies, Disease Implications, And Materials Chemistry, Robert Joseph Hilton

Theses and Dissertations

The study of ferritin includes a rich history of discoveries and scientific progress. Initially, the composition of ferritin was determined. Soon, it was shown that ferritin is a spherical, hollow protein. Eventually, over several decades of research, the structure and some function of this interesting protein was elucidated. However, the ferritin field was not completely satisfied. Today, for example, researchers are interested in refining the details of ferritin function, in discovering the role of ferritin in a variety of diseases, and in using ferritin for materials chemistry applications. The work presented in this dissertation highlights the progress that we have …

Water In Protein Cavities: Free Energy, Entropy, Enthalpy, And Its Influences On Protein Structure And Flexibility, Hongtao Yu

LSU New Orleans Theses and Dissertations

Complexes of the antibiotics novobiocin and clorobiocin with DNA gyrase are illustrative of the importance of bound water to binding thermodynamics. Mutants resistantto novobiocin as well as those with a decreased affinity for novobiocin over clorobiocinboth involve a less favorable entropy of binding, which more than compensates for amore favorable enthalpy, and additional water molecules at the proteinligandinterface.Free energy, enthalpy, and entropy for these water molecules were calculated by thermodynamicintegration computer simulations. The calculations show that addition of thewater molecules is entropically unfavorable, with values that are comparable to the measuredentropy differences. The free energies and entropies correlate with the …

Synthesis Of Chiral Intermediates By Deritivization Of Monosaccharides, Sanjeeva Dodlapati

LSU New Orleans Theses and Dissertations

Conformationally constrained bicyclic amino acids are invaluable in the synthesis of natural products and peptidomimetics. Aeruginosins contain novel bicyclic amino acid, 2--‐carboxy--‐6--‐hydroxyl octahydrindole (Choi) as the core structure. Aeruginosins are tetra peptide serine protease inhibitors isolated from marine sponges and cyanobacterial water blooms. Rigid bicyclic amino acid(Choi)is an essential core structure, which strongly influences biological activity of aeruginosin family members. Aeruginosins showed promising inhibitory activity against thrombin, trypsin, and factor VIIa. Thrombin and factor VIIa play a major role in blood clotting cascade; excessive coagulation leads to thrombosis and other cardiovascular diseases. Several research groups have reported a number of …

Characterization Of The Desorption Electrospray Ionization Mechanism Using Microscopic Imaging Of The Sample Surface, Michael Craig Wood

Theses and Dissertations

Desorption electrospray ionization (DESI) is an ambient ionization technique for mass spectrometry. This solvent based desorption ion source has wide applicability in surface analysis with minimal sample preparation. Interest in improving detection limits, broadening applications, and increasing the spatial resolution for chemical imaging has led to studies of the DESI mechanism. An inverted microscope has been used to image interactions between the DESI spray and test analytes on a glass surface. Microscopic images recorded with millisecond time resolution have provided important insights into the processes governing analyte transport and desorption. These insights are the basis of a rivulet-based model for …

The Characterization Of Avian Polyomavirus, Satellite Tobacco Mosaic Virus, And Bacteriophage Cw02 By Means Of Cryogenic Electron Microscopy, Peter S. Shen

Theses and Dissertations

Viruses are the most abundant biological entity in the biosphere and are known to infect hosts from all domains of life. The aim of my work is to identify conserved and non-conserved features among the capsid structures of related and divergent icosahedral viruses via cryogenic electron microscopy, sequence analysis, molecular modeling, and other techniques. Bird polyomaviruses often cause severe disease in their hosts whereas mammalian polyomaviruses generally do not. Avian polyomavirus is a type of bird polyomavirus with an unusually broad host range compared to the restricted tropism of other polyomaviruses. Although most polyomaviruses have a conserved, rigid capsid protein …

Synthesis Of (±)-Cyclophostin, (±)-Cyclipostin P, Their Phosphonate Analogs And New Chemistry Of Vinyl Phosphonates, Raj Kumar Malla

Dissertations

This work is divided into 2 parts: a) total synthesis of (±)-cyclophostin, (±)-cyclipostin P and their monocyclic analogs b) development of a metathesis based methodology for transformation of vinyl phosphonates. Cyclophostin (1) and cyclipostins (2) are bioactive natural bicyclic organophosphates. Cyclophostin is a powerful inhibitor of acetyl cholinesterase (AChE), whereas members of the cyclipostins are potent inhibitors of hormone sensitive lipase (HSL). Cyclophostin (1) and cyclipostin (2) have the same structural core unit, but different phosphate ester substituents. While cyclophostin is a methyl ester, the members of the cyclipostins are phosphate esters of different alkyl groups of various length and …

Characterization Of Uranium Species In Sediments Under Iron And Sulfate Reducing Conditions Using Synchrotron-Based Techniques, Don Q. Pham, John Bargar

STAR Program Research Presentations

Uranium is one of the most common and problematic contaminants at legacy Department of Energy sites. Groundwater contamination is particularly problematic because it occurs at depth, is present in large volumes, and cannot be easily accessed for clean-up. One method of remediation being investigated is the bioreduction of soluble U(VI) to insoluble U(IV) complexes through the in-situ stimulation of metal-reducing bacteria. Understanding the structure of these uranium complexes can help us determine their fate and stability in groundwater and map out the biological process of uranium reduction by metal-reducing bacteria. In this study, we used the synchrotron-based techniques, X-ray absorption …

Spectroscopic Properties Of Lanthanide (Iii) Compounds In Aqueous And Ionic Media, Orissa A. Burghard, Sayandev Chatterjee, Zheming Wang, Samuel A. Bryan

STAR Program Research Presentations

Lanthanide containing materials are receiving increasing attention due to their wide range of potential applications including bioanalytical imaging, dye-sensitized solar cells, nano-biotechnology and catalysis. The unique spectroscopic properties (intense and sharp emission bands with high color purity and high quantum efficiency) of lanthanides make them strong candidates for use as bio-markers or selective detectors. The attractiveness of lanthanides as future imaging agents as well as recent interest in their potential use in biological media has increased the need to understand the behavior of lanthanides in the presence of other ions or in ionic media.

The complexity of the biological media …

Synthesis And Structure Of A Substituted Pyridazine, Kiranmai Byrichetti

Masters Theses & Specialist Projects

Pyridazines are heterocyclic compounds with an N-N bond in their ring structure. Heterocyclic aromatic compounds are of great interest as a result of their novel properties and commercial applications. Our current research is focused on the potential role of pyridazines in next generation electronic devices that utilize organics as the semiconducting material. The synthesis of 5, 6-fused ring pyridazines beginning from fulvenes (Scheme 1) is described herein. These fused heterocycles will serve as synthetic models and building blocks for potential organic or organometallic conducting polymers.

Our goal was to modify the route of Snyder et al. previously reported for the …

Isu Chem-Letter, Fall 2011, Illinois State University, Department Of Chemistry

Chem Letter

Newsletter of the Illinois State University Department of Chemistry

Determination Of Hexamethylene Bisacetamide, An Antineoplastic Compound, In Mouse And Human Plasma By Lc–Ms/Ms, Kerri M. Smith, Wannarasmi Ketchart, Xiang Zhou, Monica M. Montano, Yan Xu

Chemistry Faculty Publications

Hexamethylene bisacetamide (HMBA) is a polar compound which has recently been discovered to have antineoplastic activity by up-regulating the expression of an endogenous antiproliferative breast cancer protein, HEXIM1 (hexamethylene bisacetamide inducible protein 1) in vivo. HMBA has been shown in the past to induce terminal differentiation in multiple leukemia types at a concentration of 2–5 mM, but its phase I and II clinical trials were largely unsuccessful due to serious side effects (notably, thrombocytopenia) with dose escalation. In this work, a sensitive and simple LC–MS/MS method for direct determination of HMBA in mouse and human plasma is described. Plasma samples …

In Vitro And In Vivo Effects Of A Cyclooxygenase-2 Inhibitor Nimesulide Analog Jcc76 In Aromatase Inhibitors-Insensitive Breast Cancer Cells, Bo Zhong, Xiaohan Cai, Xing Yi, Aimin Zhou, Shiuan Chen, Bin Su

Chemistry Faculty Publications

Third generation aromatase inhibitors (AIs) are more effective than tamoxifen in the treatment of estrogen receptor (ER) positive breast cancer. However, long-term use of AIs commonly results in resistance. We examined whether compound JCC76{Cyclohexanecarboxylic acid [3-(2,5-dimethyl-benzyloxy)-4-(methanesulfonyl-methyl-amino)-phenyl]-amide}, an analog of Cyclooxygenase-2 (COX-2) inhibitor nimesulide, can inhibit the growth of AI-insensitive breast cancer cells and the mechanisms by which the compound affects cell proliferation. LTEDaro (long term estrogen deprived MCF-7aro cell) cells, which are a model for AI resistance, were used in this study. JCC76 effectively inhibited LTEDaro cell proliferation with an IC50 of 2.75 ± 0.31 μM. Further investigations reveal that …

Mercury Deposition In Southern New Hampshire, 2006–2009, M. A. S. Lombard, J. G. Bryce, Huiting Mao, R. Talbot

Earth Sciences

The atmospheric deposition of mercury (Hg) occurs via several mechanisms including wet, dry, and occult processes. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, event-based wet deposition samples and reactive gaseous Hg (RGM) measurements were collected for approximately 3 years at Thompson Farm (TF), a near-coastal rural site in Durham, NH, part of the University of New Hampshire AIRMAP Observing Network. Total aqueous mercury exhibited seasonal patterns in Hg wet deposition at TF. The lowest Hg wet deposition was measured in the winter with an average total seasonal deposition of 1.56 μg m^{−2 …}

Single-Step Biofriendly Synthesis Of Surface Modifiable, Near-Spherical Gold Nanoparticles For Applications In Biological Detection And Catalysis, Vivek D. Badwaik

Masters Theses & Specialist Projects

There is an increased interest in understanding the toxicity and rational design of gold nanoparticles (GNPs) for biomedical applications in recent years. Such efforts warrant reliable, viable, and biofriendly synthetic methodology for GNPs with homogeneous sizes and shapes, particularly sizes above 30 nm, which is currently challenging. In the present study, an environmentally benign, biofriendly, singlestep/ single-phase synthetic method using dextrose as a reducing and capping agent in a buffered aqueous solution at moderate temperature is introduced. The resulting GNPs are near-spherical, stable, catalytically active, place exchangeable, and water-soluble within the size range of 10-120 nm. The added advantage of …

Creation Of Post Ap Chemistry Class, Julian Medrano

Theses and Dissertations - UTB/UTPA

The creation of a Post AP Chemistry Class to be taught at the high school level for grade 12 students is discussed. The class is to be taught under the supervision of the University of Texas Pan American professors and taught by an MS Chemistry teacher, in order to better transition students into upper level chemistry courses beyond Chemistry 1401 and 1402.

Best Organization Hosts First Research Symposium, Samantha Snively

Lake Union Herald

No abstract provided.

High Yield Synthesis Of Positron Emission Tomography Ligands For Metabotropic Glutamate Receptor Imaging, Saraanne E. Hitchcock

Department of Chemistry: Dissertations, Theses, and Student Research

Positron Emission Tomography (PET) is a powerful and non-invasive imaging technique used for human and animal organ imaging. Currently, the market for PET is project to reach $5.4 billion per year by 2015.5 This research focuses on the direct incorporation of [18F]-fluoride into PET ligands. The widespread use of PET imaging is currently frustrated, in part, by the lack of efficient fluorination chemistry.

Glutamate, one of the 20 most abundant naturally occurring amino acids, serves as a neurotransmitter in the central nervous system. Glutamate functions in this capacity by binding to ionotropic and metabotropic receptors. Metabotropic receptors are Gcoupled proteins …

A Large-Scale Synthesis And Characterization Of Quaternary Cuinₓga₁₋ₓs₂ Chalcopyrite Nanoparticles Via Microwave Batch Reactions, Chivin Sun, Richard D. Westover, Gary J. Long, Cyril Bajracharya, Jerry D. Harris, Alexander Punnoose, René G. Rodriguez, Joshua J. Pak

Chemistry Faculty Research & Creative Works

Various quaternary CuIn_xGa_1-xS₂ (0≤x≤1) chalcopyrite nanoparticles have been prepared from molecular single-source precursors via microwave decomposition. We were able to control the nanoparticle size, phase, stoichiometry, and solubility. Depending on the choice of surface modifiers used, we were able to tune the solubility of the resulting nanoparticles. This method has been used to generate up to 5g of nanoparticles and up to 150g from multiple batch reactions with excellent reproducibility. Data from UV-Vis, photoluminescence, X-ray diffraction, TEM, DSC/TGA-MS, and ICP-OES analyses have shown high reproducibility in nanoparticle size, composition, and bandgap.

Synthesis Of A Chemical Probe For Identification Of Ger Receptor Proteins Of Bacillus Anthracis, Hyelee Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus anthracis,a gram positive, endospore-forming, rod-shaped, aerobic bacterium, is the causative agent of anthrax. A key step in the pathogenic cycle is the spore germination, where the dormant spore transforms into a metabolically active cell. This allows B. anthracis to proliferate and secrete toxins. It is believed that spore germination is triggered when small molecules, known as germinants, are recognized by germination (Ger) receptor proteins located in the inner membrane of spores. Most Ger proteins are encoded by tricistronic operons, resulting in three distinct products, the A-, B-, C-subunits. Genomic sequencing showed that B. anthracis has seven ger receptor …

Self-Repairable Polymeric Networks: Synthesis And Network Design, Biswajit Ghosh

Dissertations

This dissertation describes the design, synthesis and development of a new class of polymeric networks that exhibit self-repairing properties under UV exposure. It consists of two parts: (a) modification and synthesis of oxetane (OXE), and oxolane (OXO) substituted chitosan (CHI) macromonomer, and (b) design, and synthesis of self-repairing polyurethane (PUR) networks consisting of modified chitosan. Unmodified CHI consisting of acetamide (-NHCOCH₃), primary hydroxyl (-OH), and amine (-NH₂) functional groups were reacted with OXE or OXO compounds under basic conditions in order to substitute the 1° –OH groups, and at the same time, convert -NHCOCH₃ functionalities …

Precision Synthesis Of Functional Materials Via Raft Polymerization And Click-Type Chemical Reactions, Joel Diez Flores

Dissertations

The need to tailor polymeric architectures with specific physico-chemical properties via the simplest, cleanest, and most efficient synthetic route possible has become the ultimate goal in polymer synthesis. Recent progress in macromolecular science, such as the discoveries of controlled/“living” free radical polymerization (CRP) methods, has brought about synthetic capabilities to prepare (co)polymers with advanced topologies, predetermined molecular weights, narrow molecular weight distributions, and precisely located functional groups. In addition, the establishment of click chemistry has redefined the selected few highly efficient chemical reactions that become highly useful in post-polymerization modification strategies. Hence, the ability to make well-defined topologies afforded by …

Positional Control Over Nanoparticle Deposition Into Nanoholes, Moshood K. Morakinyo, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

Controlled deposition of metal nanoparticles (NPs) into lithographic patterned nanoholes has been a major challenge. Electrostatic attraction was employed in directing gold NPs of precise size into e-beam lithographically patterned holes. Citrate stabilized gold NPs with a net negative surface charge were deposited on a positively charged well-bottom surface generated by adsorption of long-chain amino-terminated organosilane N-(2-aminoethyl)-11-aminoundecyltrimethoxy- silane (AATMS). Scanning electron microscopy (SEM) results indicate that deposition of NPs into patterned holes is a function of deposition time and NPs concentration. Other factors affecting NP fill fraction are thickness of silane and resist layer and spacing between the nanoholes.

Analysis Of The Conformational Behavior And Stability Of The Sap And Tsap Isomers Of Lanthanide(Iii) Nb-Dota-Type Chelates, Gyula Tircso, Benjamin Charles Webber, Benjamin E. Kucera, Victor G. Young, Mark Woods

Chemistry Faculty Publications and Presentations

Controlling the water exchange kinetics of macrocyclic Gd(3+) chelates, a key parameter in the design of improved magnetic resonance imaging (MRI) contrast media, may be facilitated by selecting the coordination geometry of the chelate. The water exchange kinetics of the mono- capped twisted square antiprism (TSAP) being much closer to optimal than those of the mono capped square antiprism (SAP) render the TSAP isomer more desirable for high relaxivity applications. Two systems have been developed that allow for selection of the TSAP coordination geometry in 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-type Gd(3+) chelates, both based upon the macrocycle nitrobenzyl cyclen. In this paper …

An Investigation Of The Effectiveness Of Gestures To Enhance Concept Retention In Chemistry Instruction, Jeffrey Lamb

All Theses

The emergence of embodied cognition as a theory of learning has placed new emphasis on the interdependent relationship between what the mind perceives and what the body experiences. Movement and objects in the physical environment take on significant roles in the process of learning within this view and the role of gesturing in cognition has become increasingly interesting. Significant research suggests that the physical process of gesturing is connected to how the mind processes information. Gesturing during the recall of information is a universally known phenomena and one that seems to aid in the process of recall. More recent findings …

Bridging The Gap Between Structures And Properties: An Investigation And Evaluation Of Students' Representational Competence, Sonia Underwood

All Dissertations

The heart of learning chemistry is the ability to connect a compound's structure to its function; Lewis structures provide an essential link in this process. In many cases, their construction is taught using an algorithmic approach, containing a set of step-by-step rules. We believe that this approach is in direct conflict with the precepts of meaningful learning. From a sequential, mixed methods study, we found that students have much difficulty constructing these structures and that the step-by-step rules do not make use of students' relevant prior knowledge. This causes students to develop 'home grown' rules when unsure of how to …

Semifluorinated Aromatic Ether Polymers Segmented With Polyethylene Glycol (Peg), Dakarai Brown

All Dissertations

Aromatic trifluorovinyl ether (TFVE) monomers are the precursors for perfluorocyclobutyl (PFCB) aryl ether polymers and fluoroethylene/vinylene alkyl/aryl ether (FAE) polymers. PFCB aryl ether polymers are prepared by 2π + 2π cycloaddition of aromatic TFVE monomers. FAE polymers are prepared by nucleophilic addition of dual functional aryl or alkyl alcohols to aryl TFVE monomers. PFCB aryl ether and FAE polymers are amorphous, have excellent processability, high thermal stability, optical clarity, and tunability using a variety of (co)monomers. In this dissertation several novel monomers, polymers, and blends were prepared by incorporation of polyethylene glycol (PEG) or PEG precursors.
Chapter 1 contains the …

Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum

All Dissertations

Ever since the discovery of conducting polymers (CPs)in the late 1970s, organic conjugated materials and polymers is one of the most popular and fascinating research area among the scientists due to the remarkably unique properties and broad range of applications of (CPs), notably organic photovoltaic (OPVs), organic or polymer based light emitting devices (OLEDs / PLEDs), field effect transistors (FETs), nonlinear optical (NLO) devices and sensor for biologically relevant analytes, metal ions and anions. Optical properties of these materials depend on intra / interchromophoric interaction, geometry and relative orientation in space. Detailed study of such materials can also help us …

Structural Basis For Sequence Specific Dna Binding And Protein Dimerization Of Hoxa13, Yonghong Zhang, Christine A. Larsen, H. Scott Stadler, James B. Ames

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

The homeobox gene (HOXA13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of genes during embryonic morphogenesis. Here we present the NMR structure of HOXA13 homeodomain (A13DBD) bound to an 11-mer DNA duplex. A13DBD forms a dimer that binds to DNA with a dissociation constant of 7.5 nM. The A13DBD/DNA complex has a molar mass of 35 kDa consistent with two molecules of DNA bound at both ends of the A13DBD dimer. A13DBD contains an N-terminal arm (residues 324 - 329) that binds in the DNA minor groove, and a C-terminal helix (residues …

A Theoretical Investigation Examining Dna Conformational Changes And Their Effects On Glycosylase Function, Allyn Brice

All Dissertations

Glycosylase enzymes initiate the process of base excision repair (BER) in order to prevent the irreversible modification of the genome. In the BER process a damaged DNA base is recognized, removed from the DNA sequence, and then the remaining abasic site is repaired. Glycosylase enzymes are responsible for the base recognition mechanism and catalysis of the base excision. One of the most studied glycosylase superfamilies is uracil DNA glycosylase (UDG). The UDG superfamily has demonstrated specificity for excising uracil, which is the deamination product of cytosine, from DNA sequences of prokaryotes and eukaryotes. Mismatch-specific uracil DNA glycosylase (MUG) is a …