Physical Sciences and Mathematics Commons^™

Part I. The Development Of Non-Secosteroidal Vitamin D Receptor Modulators Part Ii. The Development Of A Universal Gtp-Ase Assay, Kelly Ann Teske

Theses and Dissertations

The vitamin D receptor is a nuclear hormone receptor that regulates cell proliferation, cell differentiation, calcium homeostasis and immunomodulation. The receptor is activated by the vitamin D metabolite, 1,25-dihydroxyvitamin D3, which induces a cascade of events including the recruitment of coactivators that activate transcription of specific VDR target genes. Thousands of VDR agonists have been synthesized based on the secosteroid scaffold of 1,25-dihydroxyvitamin D3. However, most of these ligands are metabolically unstable, have sub-optimal drug-like properties, and induce hypercalcemia in vivo. The limited numbers of VDR antagonists reported bear the same secosteroid scaffold and thus exhibit similar problems encountered by …

Enantiospecific Stereospecific Strategy For The Total Synthesis Of Sarpagine And Macroline Related Oxindole Alkaloids: First Total Synthesis Of Affinisine Oxindole, Isoalstonisine, Alstofoline, Macrogentine, N(1)-Demethylalstonisine, Alstonoxine A And Second Generation Synthesis Of Alstonisine, German Oscar Fonseca Cabrera

Theses and Dissertations

The (7R)-sarpagine/macroline related oxindole alkaloids (-)-isoalstonisine (27) and (-)-macrogentine (31) together with the (7S)-sarpagine/macroline related oxindole alkaloids (-)-affinisine oxindole (24), (-)-alstonoxine A (19), (+)-alstonisine (8, second generation total synthesis), (+)-Na-demethylalstonisine (17) and (+)-alstofoline (18) were concisely synthesized during these studies.

These oxindole alkaloids were isolated from plants of the genus Alstonia which is characterized by the preponderance of sarpagine/macroline-type indole and oxindole alkaloids. Plants that belong to this genus are mainly distributed over tropical regions of Central America, Africa, and Asia where they are used locally in traditional medicine, for example, in the treatment of malaria and dysentery. The main …

Investigations Of Thioether Generation For S-D-Ribosyl-L-Homocysteine Synthesis, Brendan Corcoran

Master's Theses

Creation of the thioether linkage is a fundamental step for the chemical preparation of the bacterial quorum sensing molecule S-D-ribosyl-L-homocysteine (SRH). Although previous preparations of SRH and its analogues have been reported in the literature, they employ assorted methods with varied results. Therefore, a reassessment of the methodology used for synthetic preparation of the thioether bond in SRH-like molecules is here considered. This work examines four methods of thioether generation following two mechanisms, bimolecular nucleophilic substitution (S_N2) and radical-initiated thiol-ene coupling, in an attempt to generate SRH in a more efficient and reproducible manner. Both mechanisms address …

Synthesis And Characterization Of Support-Modified Nanoparticle-Based Catalysts And Mixed Oxide Catalysts For Low Temperature Co Oxidation, Andrew Justin Binder

Doctoral Dissertations

Heterogeneous catalysts are responsible for billions of dollars of industrial output and have a profound, if often understated, effect on our everyday lives. New catalyst technologies and methods to enhance existing catalysts are essential to meeting consumer demands and overcoming environmental concerns. This dissertation focuses on the development of catalysts for low temperature carbon monoxide oxidation. CO [carbon monoxide] oxidation is often used as a probe reaction to test overall oxidation activity of a given catalyst and is an important reaction in the elimination of toxic pollutants from automotive exhaust streams. The work included here presents three new heterogeneous catalysts …

Asymmetric Synthesis Of Tryptophan Driviatives And Its Application To Streamlined Synthesis Of Tryprosatain A And B, Matthew Huisman

Theses and Dissertations

Tryprostatins have been shown to be potential antitumor antimitotic agents. Tryprostatins have been isolated from the fermentation broth of marine fungal strain Aspergillus fumigatus in trace amounts. Our lab has developed a phase-transfer-catalyzed asymmetric alkylation reaction to produce protected tryptophans (Trp) with high enantioselectivity (90-95% ee) as synthetic precursors to Tryprostatins. Studies of Tryprostatins indicate that manipulation of ring-A may cause enhanced activity. We propose a general synthetic route to several new tryprostatins that may be tolerant to ring-A analogues of gramine utilizing achiral reactants. The synthesis of Tryprostatin B has been completed with 20% overall yield in 7 steps. …

A New Synthesis Of Bis (4-Tert-Butylphenyl) Iodonium Hexafluoroantimonate; A Known Catalyst For Photopolymerization, Matthew C. Salvi

Chemistry Master’s Theses

This thesis describes a novel reaction protocol for the synthesis of bis (4-tert-butylphenyl) iodonium (BtPhI) hexafluoroantimonate (2) via the formation of diacetoxy (t-butylphenyl)-λ3-iodane (1). It is also important to provide a safe and robust reaction procedure for future scaled-up production.

Synthesis Of Cryptands For Eu2+-Containing Complexes, Chengcheng Wang

Wayne State University Theses

Eu2+-containing complexes have considerable applications in synthetic chemistry, medical diagnosis, and materials science. However, Eu2+ is easily oxidized in solution when exposed to air. Allen and coworkers have demonstrated that Eu2+ can be stabilized by functionalized cryptands. Based on this idea, I focused my research on synthesizing cryptands. The progress towards synthesizing several modified cryptands is described in the thesis. The Eu2+-containing complexes of these cryptates have potential applications as magnetic resonance imaging contrast agents, luminescent materials, and magnetic materials.

Synthesis, Surface Functionalization, And Biological Testing Of Iron Oxide Nanoparticles For Development As A Cancer Therapeutic, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles are highly researched for their use in biomedical applications such as drug delivery, diagnosis, and therapy. The inherent biodegradable and biocompatible nanoparticle properties make them highly advantageous in nanomedicine. The magnetic properties of iron oxide nanoparticles make them promising candidates for magnetic fluid hyperthermia applications. Designing an efficient iron oxide nanoparticle for hyperthermia requires synthetic, surface functionalization, stability, and biological investigations. This research focused on the following three areas: optimizing synthesis conditions for maximum radiofrequency induced magnetic hyperthermia, designing a simple and modifiable surface functionalization method for specific or broad biological stability, and in vitro and in …

Investigating The Synthesis Of Heterocycles Via Gold Catalyzed Cyclizations And Cyclo-Dehydrating Reactions, Katherine L. Childers

Undergraduate Honors Thesis Projects

The goal of this project was to study novel synthetic procedures for heterocycles. This was achieved through a two-part investigation. In the first part, a variety of conditions for the gold catalyzed cyclization of allenes were studied. This work was focused on the lesser studied intermolecular reactions of allenes. A variety of allenes were synthesized, and then reacted with 1,3-dipoles and a gold catalyst. These reactions were determined to be unsuccessful through the analysis of nuclear magnetic resonance spectroscopy data. In the second part of this study, the synthesis of 1,3,4-oxadiazoles was investigated. Several cited procedures were examined to determine …

Total Synthesis Of Clavatadine A Analogs To Produce A Viable Reversible Inhibitor For Factor Xia, Christopher E. Malmberg

All Master's Theses

Cardiovascular disease has quickly become a major health concern in the United States, with numerous citizens dying from cardiovascular disease each year. Older medications, while effective against cardiovascular disease, are problematic to prescribe. A recently isolated natural product, clavatadine A, selectively inhibits human blood coagulation factor XIa. As a result, the synthesis and biological testing of clavatadine A and synthetic clavatadine A analogues that selectively inhibit factor XIa would represent a new direction in cardiovascular disease research. A potent and selective factor XIa inhibitor has the potential to be a safer replacement for current anticoagulants, such as Warfarin, Pradaxa^{® …}

Nanoscale Gumbos: Size-Control, Characterization, And Applications As Enantioselective Molecularly Imprinted Polymers And Fluorescent Materials, Suzana Hamdan

LSU Doctoral Dissertations

Nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) have been introduced into the scientific literature through many analytical, biological, and technological applications. These nanomaterials, referred to as nanoGUMBOS, have been shown to display a number of interesting properties including fluorescence, magnetism, tumor targeting, and optoelectronic properties. Herein, we present major studies on nanoGUMBOS including synthesis and size-control, chiral molecular imprinting in polymers, as well as investigation of optical properties and quantum yield of fluorescent semiconductor-based nanoGUMBOS. Various strategies were introduced for production of well-defined nanoGUMBOS. Specifically, several methods based on sonochemistry, microwave, cyclodextrin, and surfactant-assisted …

Biodegradable Poly(Ester Urea's) Scaffold Sponges Containing Platelet-Rich Plasma For Targeted Tendon-Bone Fixation, Alex B. Ellenberger Mr.

Williams Honors College, Honors Research Projects

In this report the synthesis and characterization of L-valine and L-isoleucine poly(ester ureas) (PEUs) for future use in the synthesis of biodegradable PEUs sponges will be discussed. The method of monomer and polymer synthesis will be explained along with the characterization of the monomer and polymer products. This characterization will be done by the use of Nuclear Magnetic Resonance (NMR) and Size Exclusion Chromatography (SEC). NMR is a quick and convenient method for determining structure and purity of the monomer and polymer products. SEC gives the number average molecular weight, which is the statistical average molecular weight of all the …

Synergistic Properties-Driven Synthesis Of Aluminides, Antiomonides, And Bioceramics, Pilanda Watkins-Curry

LSU Doctoral Dissertations

The synthesis, characterization, and properties of selected intermetallics and ceramic materials are presented in this dissertation. In our quest to grow single crystal intermetallics from the metal flux technique, new strategies were employed to avoid thermodynamically stable phases and to ensure sample homogeneity of the crystalline product for structure elucidation and accurate measurements of their magnetic and electrical properties. The relationship between the complex crystal structures and magnetic properties are reported for LnCo2Al8 (Ln = La-Nd, Sm, Yb), CeCo2-xMnxAl8 (0 < x < 1), and Pr2Fe4-xCoxSb5 (1 ≤ x < 3). The discovery of magnetic frustration in LnCo2Al8 (Ln = Ce, Nd) and complex magnetic ordering coupled with large positive magnetoresistance of up to 150% and 60% at 200 K with relatively low field of H = 1 T in Pr2Fe4-xCoxSb5 (x ≈ 2 and 2.5) is also reported. The demand of new inorganic solid materials as scaffolds for the engineering of bone tissue has led to the synthesis of calcium magnesium silicates such as, diopside (CaMgSi2O6), akermanite (Ca2MgSi2O7), monticellite (CaMgSiO4), and merwinite (Ca3Mg(SiO4)2)) for studying dimensionality and mechanical properties. This dissertation highlights the synergism of solid state chemistry at the interface of condensed matter physics and biological engineering. The discovery of compounds with tunable magnetic, electrical, and mechanical properties will be described herein.

Synthesis With Hypergraphs, Christopher Thomas Alvin

LSU Doctoral Dissertations

Many problems related to synthesis with intelligent tutoring may be phrased as program synthesis problems using AI-style search and formal reasoning techniques. The _x000C_first two results in this dissertation focus on problem synthesis as an aspect of intelligent tutoring systems applied to STEM-based education frameworks, specifically high school geometry. Given a geometric _x000C_figure as input, our technique constructs a hypergraph representing logical deduction of facts, and then traverses the hypergraph to synthesize problems and their corresponding solutions. Using similar techniques, our third result is focused on exhaustive synthesis of molecules. This synthesis process involves bonding sets of basic, molecular `fragments' …