Chemistry Commons^™

Spatial And Temporal Variations In The Air-Sea Carbon Dioxide Fluxes Of Florida Bay, Christopher Michael Dufore

USF Tampa Graduate Theses and Dissertations

The flux of CO2 between the ocean and the atmosphere is an important measure in determining local, global, and regional, as well as short term and long term carbon budgets. In this study, air-sea CO2 fluxes measured using a floating chamber were used to examine the spatial and temporal variability of CO2 fluxes in Florida Bay. Measurements of dissolved inorganic carbon and total alkalinity obtained concurrently with chamber measurements of CO2 flux allowed calculation of ΔpCO2 from flux measurements obtained at zero wind velocity. Floating chamber measurements of ΔpCO2 were subsequently coupled with wind speed data to provide a simple …

Solid-State Synthesis Of Imide Ligands For The Self-Assembly Of Metal-Organic Materials, Jason Alexander Perman

USF Tampa Graduate Theses and Dissertations

In this research project, reduction or complete elimination of organic solvents is explored in the synthesis of cyclic imides using a technique that brings reagents into favorable position to react. Cocrystal Controlled Solid-State Synthesis (C³S^y3), takes advantage of supramolecular interactions such as hydrogen bonding and π-π stacking to form a cocrystal which can sequential be heated to complete the condensation reaction and produce a desirable product. Twenty-five successful condensation reactions result in high and clean yield.

C³S^y3 of cyclic imides with auxiliary hydrogen bonding moieties like carboxylic acid, carboxylate or pyridyl groups are …

Probing Molecules In Confined Space, Carissa Marie Vetromile

USF Tampa Graduate Theses and Dissertations

Despite the plethora of information regarding cellular crowding and its importance on modulating protein function the effects of confinement on biological molecules are often overlooked when investigating their physiological function. Recently however, the encapsulation of biomolecules in solid state matrices (NafionTM, sol-gels, zirconium phosphate,etc.) has increased in importance as a method for examining protein conformation and dynamics in confined space as well as novel applications in biotechnology. Biotechnological applications include, but are not limited to, bioremediation, biosensors, biocatalysts, etc. In order to better utilize solid state materials as substrates for biological molecules an understanding of the effects of encapsulation on …

Synthesis Of Small Molecule Inhibitors Of Janus Kinase 2, Phosphodiesterase Iv, Gabaa And Nmda Receptors: Investigation Of Mcmurry, Mannich And Chemoenzymatic Strategies, Meghanath Gali

USF Tampa Graduate Theses and Dissertations

Stilbenoids possess a wide range of biological properties such as, anticancer, antiplatelet aggregation, antiestrogenic, antibacterial, antifungal and antiatherogenic, etc. Owing to these therapeutic values, a great deal of attention attracted in the synthesis of derivatives of stilbenes. During the course of the study, G6 a novel stilbenoid was discovered, through high throughput screening, to be a potent inhibitor of mutated JAK2-V617F. The mutated JAK2 variant has been implicated in various myeloproliferative disorders (MPDs) including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) has been targeted by therapeutics. Chapter 2 describes the synthesis of analogs of the stilbenoid G6 …

Electronic Structure Characterization Of Nanocrystalline Surfaces And Interfaces With Photoemission Spectroscopy, Sebastian Gutmann

USF Tampa Graduate Theses and Dissertations

In this study, photoemission spectroscopy (PES) was used to investigate the electronic properties of nanocrystalline titanium dioxide (TiO₂), zinc oxide (ZnO), and cadmium selenide (CdSe). Electrospray deposition technique enabled the preparation of thin films in vacuum from a dispersion prepared outside the vacuum chamber. This method also allowed the step-wise formation of interfaces and the monitoring of the evolution of the electronic structure with intermittent PES characterization.

The work function of nanocrystalline TiO₂ and ZnO was measured with ultraviolet photoemission spectroscopy (UPS) and low-intensity x-ray photoemission spectroscopy (LIXPS). Measurements on environmentally contaminated surfaces revealed an instantaneous and …

Natural Product Drug Discovery Against Tropical Diseases, Wai Sheung Ma

USF Tampa Graduate Theses and Dissertations

This dissertation describes the isolation of secondary metabolites from natural origins through a series of chromatographic techniques and spectrometric characterization in the effort of drug discovery. The isolated compounds obtained were used as drug leads against tropical diseases, namely malaria and leishmaniasis. While first chapter offers an introduction on the use of a natural product by itself as an effective therapeutic and its role on inspiring the discovery of new drugs, the later chapters will concentrate on isolation and characterization of bioactive natural products from an Antarctic sponge and mangrove endophytic fungi during the dissertation work.

The second chapter describes …

Chemical Investigation Of The Antarctic Marine Invertebrates Austrodoris Kerguelenensis & Dendrilla Membranosa And The Antarctic Red Alga Gigartina Skottsbergii, John Alan Maschek

USF Tampa Graduate Theses and Dissertations

The marine realm and, in particular, the Antarctic benthos is largely unexplored and understudied. The chemical investigation reported herein reveals not only the biodiversity, but how that biodiversity manifests remarkable chemical diversity. In our continuing study of the nudibranch Austrodoris kerguelenensis, we have isolated a diverse suite of diterpenoid glyceride esters, palmadorins D - S (2.32 - 2.47), one of which is the first reported halogenated diterpene from a dorid nudibranch. Utilizing genomic data from collaborators, we have investigated the chemical diversity from phylogenetically unique specimens collected in close proximity to one another. Chemical groupings based on comparison of LC/MS …

Crystal Engineering Of Pharmaceutical Cocrystals, Sreya Mukherjee

USF Tampa Graduate Theses and Dissertations

Pharmaceutical cocrystals use principles of crystal engineering for the design of crystalline forms of drugs and can improve their solubility, bioavailability, stability and other important properties without changing the efficacy of the drug. Herein reported are pharmaceutical cocrystals of two API's, caffeine and Pentoxifylline.

Research has indicated that caffeine has the ability to reverse AB; plaque deposition in the brain (believed to be the primary cause of Alzheimer's pathogenesis) and thus revert memory and improve cognitive impairment. But owing to the fast absorption rate and short half life, a controlled release formulation of caffeine would be clinically beneficial. Thus, novel …

Sol-Gel Resorcinarene Sorbent For Capillary Microextraction Coupled To Gas Chromatography, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

For the first time, octahydroxyl methylresorcinarene with four hexyl groups on the lower rim was utilized in the in-situ preparation of a silica-based sol-gel organicinorganic hybrid coating for sample preconcentration by capillary microextraction (CME). Tetraethoxysilane (TEOS) was chosen as a sol-gel precursor to create a crosslinked sol-gel network via acid-catalyzed hydrolytic polycondensation reactions. Sol-gel chemistry helped in the in situ preparation of resorcinarene-containing extraction phase in the form of a surface coating. It also provided an effective means to chemically bind the coating to the inner surface of fused silica capillary via condensation of the hydroxyl groups in the sol-gel …

Synthesis And Characterization Of Self-Healing Poly (Carbonate Urethane) Carbon-Nanotube Composites, Roger Wesley Bass

USF Tampa Graduate Theses and Dissertations

Synthesis of high molar mass polycarbonate polyurethanes using a novel polyol is described. The resulting elastomers demonstrate excellent mechanical properties as well as the capability to re-heal after rupture without the addition of additives or imbedded healing agents. The self-healing functionality is shown to greatly improve with the addition of up to 1% single and multi-walled carbon nanotubes. The interface of the carbon nanotubes and self-healing polymer are probed using Raman techniques and provide an insight into how the self-healing actions are improved with the addition of carbon nanotubes.

Synthesis of polycarbonate polyurethanes and carbon nanotube composites using a novel …

Lead Discovery And Optimization Strategies Towards The Development Of 4(1h)-Quinolones And 1,2,3,4-Tetrahydroacridone Analogs With Antimalarial Activity, Richard Matthew Cross

USF Tampa Graduate Theses and Dissertations

The goal of our research endeavor was to successfully employ modern lead discovery and optimization strategies towards the development and identification of compounds possessing antimalarial activity. Preliminary data from in vitro screening at the Walter Reed Army Institute of Research identified several chemotypes including 4(1H)-quinolones and 1,2,3,4-tetrahydroacridones to have potent antimalarial activities. Multiple synthetic routes were devised and implemented which enabled the rapid preparation and isolation of over 400 structurally diverse 4(1H)-quinolones and 1,2,3,4-tetrahydroacridones.

Our research towards discovering and optimizing antimalarials was inspired from the severe impact malaria has had on our planet especially on impoverished countries. There are over …

Guanidines, Amidines And Carbamides As Novel Sigma Receptor Ligands For Post-Stroke Therapeutics, Michelle Yolanda Cortes-Salva

USF Tampa Graduate Theses and Dissertations

Stroke is the 3^rd leading cause of death in the United States. For this reason, it has become our goal to find a drug that is capable of reestablishing intracellular and extracellular Ca⁺² flux upon direct binding to the sigma receptor, which can be delivered easily and efficiently. Our active research focuses the development of guanidine analogues that can serve as therapeutic drugs which target sigma 1 and sigma 2 receptors having a direct effect on Ca⁺² levels on the cell. The use of symmetrical guanidine analogues such as N,N'-di-o-tolyl guanidine (o-DTG) as therapeutic drugs for ischemic …

Synthesis And Antimicrobial Activities Of S,S'-Heterosubstituted Disulfides, Praveen Ramaraju

USF Tampa Graduate Theses and Dissertations

Antibiotic resistance is a particularly critical health concern and has increased dramatically over the past two decades. For over a decade the Turos laboratory has been designing small molecules to target pathogenic microbes such as Staphylococcus aureus and the resistant variants like methicillin-resistant Staphylococcus aureus (MRSA). Previously, N-thiolated Β-lactams, N-thiolated 2-oxazolidinones and aromatic disulfides that were synthesized in Dr. Turos' lab have shown strong activity against these bacteria. The present work describes the synthesis and antimicrobial activities of a related structural class called S,S'-heterosubstituted disulfides. For ages, sulfur (elemental) has been used as an antibacterial for controlling infestation and bacterial …

Corrole Synthesis And Catalytic Applications Toward Cobalt(Iii)-Catalyzed Epoxidation, N-H Insertion, And Cyclopropanation, Chung Sik Kim

USF Tampa Graduate Theses and Dissertations

A variety of bromocorroles, useful precusors for Pd-based cross coupling, were sucessfully synthesized in moderate to good yields. Chiral corroles were also synthesized through use of chiral amides in the aforementioned cross coupling reactions. Cobalt complexes bearing π-acceptor (CNtBu) and σ-donor (PPh3) ligands were also prepared in excellent yields. In this dissertation, cobalt (III) corrole complexes were applied to three different reaction areas: epoxidation, N-H insertion, and cyclopropanation. Cobalt(III) corroles were found to be efficient catalysts for epoxidation reactions. The epoxidation reactions can be carried out using ethyl phenyldiazoacetate, an acceptor/donor diazo compound, as a carbenoid precusor.The reaction provided highly …

Design And Synthesis Of Beta-Hairpin Peptidomimetics For Modulating Integrin Mediated Cell Adhesion, Abeta Fibrillogenesis And P53-Mdm2 Protein-Protein Interactions, Priyesh Jain

USF Tampa Graduate Theses and Dissertations

Inhibiting therapeutically important protein-protein interactions has been a tremendous challenge for medicinal chemists. The folded 3D structures of peptides and proteins, mainly comprise secondary structural elements i.e α-helices and β-sheet have created an opportunity to design small molecules and peptidomimetic inhibitors of protein-protein interaction (PPI). Hence, information about the formation and stabilization of these secondary structures is vital for designing future drugs. In this dissertation, several cyclic beta-hairpin peptidomimetics that mimic the recognition surface have been designed and synthesized as inhibitors for different targets such as integrin mediated extracellular matrix -cell adhesion in multiple myeloma, p53-MDM2 PPI, amyloid beta fibrillogenesis …

Design, Synthesis & Biological Activity Of Novel Protein Tyrosine Phosphatase (Ptp) Mimetics, Sridhar Reddy Kaulagari

USF Tampa Graduate Theses and Dissertations

Protein phosphorylation is a post translational modification of proteins in which a serine, a threonine or a tyrosine residue is phosphorylated by an enzyme, kinase. Phosphorylation of proteins is a reversible and very important regulatory mechanism that occurs in both prokaryotes and eukaryotes. Phosphorylation turns many protein enzymes on and off, preventing or causing many diseases such as diabetes, cancer and rheumatoid arthritis. The phosphorylation on tyrosine residues of proteins is essential for transmission of signals for cell growth, proliferation and differentiation. Protein tyrosine phosphatases (PTPs) in concert with protein tyrosine kinases (PTKs) regulate many signal transduction pathways by controlling …

The Design And Synthesis Of Functionalized Porphyrins And Their Applications In Group Transfer Reactions, Medicine, And Materials, Kimberly Bliss Fields

USF Tampa Graduate Theses and Dissertations

Porphyrins and their analogs are a class of chemically and biologically important compounds that have found a variety of applications in different fields such as catalysis, medicine, and materials. The physical, chemical, and biological dependence of the peripheral substituents of porphyrins on their properties has prompted great effort towards the synthesis of new porphyrins with different electronic, steric, and conformational environments. To this end, porphyrins have been prepared using a modular approach from bromo- and triflate synthons. These synthons underwent palladium-catalyzed cross-coupling with chiral amines, amides, alcohols, and boronic esters to create products that were tested for biological activity.

Metalloporphyrins …

Synthesis Of Functionalized Resorcin[4]Arene Via Click Chemistry, Ali Husain

USF Tampa Graduate Theses and Dissertations

Click chemistry is a very powerful chemical strategy that overcome carbon-carbon bond with carbon-heteroatom bond by joining small units with heteroatom links (C-X-C) using spring-loaded reactants. The Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition is a major example based on the click chemistry philosophy. This method was used for the last 10 years to join different functional groups, carbohydrates, aminoacids, polymers to calix[4]arene and resorcin[4]arene cavitands by a stable 1,2,3-triazole linkages.

Herein I describe our interest in this type of click chemistry reaction in the synthesis of dimeric capsules resorcin[4]arene via four 1,2,3-triazole linkages. Two different resorcin[4]arene derivatives were synthesized in which four …

Applications Of Molecular Dynamics Techniques And Spectroscopic Theories To Aqueous Interfaces, Anthony Green

USF Tampa Graduate Theses and Dissertations

The primary goal of spectroscopy is to obtain molecularly detailed information about the system under study. Sum frequency generation (SFG) vibrational spectroscopy is a nonlinear optical technique that is highly interface specific, and is therefore a powerful tool for understanding interfacial structure and dynamics. SFG is a second order, electronically nonresonant, polarization experiment and is consequently dipole forbidden in isotropic media such as a bulk liquid. Interfaces, however, serve to break the symmetry and produce a signal. Theoretical approximations to vibrational spectra of O-H stretching at aqueous interfaces are constructed using time correlation function (TCF) and instantaneous normal mode (INM) …

Design, Combinatorial Synthesis, And Biological Evaluation Of Novel Α-Helical Mimetics Based On Functionalized Piperazines As Antagonists Of P53/Mdm2 Interactions, Melissa Elizabeth Topper

USF Tampa Graduate Theses and Dissertations

The p53 protein promotes tumor eradication upon activation, making it an attractive target in cancer therapies. A reported 50% of all human cancers display aberrant activation of the MDM2 oncoprotein, which directly promotes tumorgenesis by inactivating the transcriptional activity of wild type p53, and is commonly associated with drug, chemo, and radio therapy resistance. Previously reported crystallographic analysis of the p53/MDM2 complex infers that the p53 protein forms a 2.5 turn amphipathic alpha helix whose hydrophobic face interacts within a deep hydrophobic cleft in the NH2-terminal domain of the globular MDM2. This suggests that the synthesis of small molecular antagonists …

Design And Combinatorial Synthesis Approach Of Non-Peptidic Trimeric Small Molecules Mimicking I, I + 4(3), I + 7 Positions Of Alpha-Helices, Mingzhou Zhou

USF Tampa Graduate Theses and Dissertations

Protein-protein interactions are key to several biological processes that facilitate signal transduction and many other processes. These interactions are involved in pathways that are critical to many human diseases. Targeting specific protein-protein interactions is a challenging goal because protein-protein interactions are predominately through hydrophobic interactions. Antagonists of the protein-protein interactions need to be perfectly fit into the binding pockets to ensure the activity. The -helical domain of the proteins behaves as the recognition motifs for numerous protein-protein, and protein-nucleic acid interactions. Research has shown that pathways of many diseases contain protein-protein interactions involving -helical domains, e.g. neurological disorders, bacterial infections, …

Structural Diversity In Crystal Chemistry: Rational Design Strategies Toward The Synthesis Of Functional Metal-Organic Materials, Amy J. Cairns

USF Tampa Graduate Theses and Dissertations

Metal-Organic Materials (MOMs) represent an important class of solid-state crystalline materials. Their countless attractive attributes make them uniquely suited to potentially resolve many present and future utilitarian societal challenges ranging from energy and the environment, all the way to include biology and medicine. Since the birth of coordination chemistry, the self-assembly of organic molecules with metal ions has produced a plethora of simple and complex architectures, many of which possess diverse pore and channel systems in a periodic array. In its infancy however this field was primarily fueled by burgeoning serendipitous discoveries, with no regard to a rational design approach …

Chemical Investigation Of The Antarctic Marine Invertebrates Synoicum Adareanum And Artemisina Plumosa, Jaime Heimbegner Noguez

USF Tampa Graduate Theses and Dissertations

Of the small percentage of organisms chemically investigated over the years as potential sources of natural products, much less is known about those from the marine realm. Despite the lack of attention they have received in comparison to terrestrial organisms, marine life have recently been found to represent a valuable source for novel bioactive compounds. Cold water marine habitats are home to a plethora of organisms that have the ability to produce secondary metabolites that exhibit a great deal of diversity in both their chemical structures and biological activities. The chemical investigation of these unique and relatively unstudied ecosystems is …

Metal-Organic Materials: From Design Principles To Practical Applications, Mohamed H. Alkordi

USF Tampa Graduate Theses and Dissertations

The works presented herein outline rational design approaches towards construction of solid state materials with great potentials to answer some of current demanding applications. Specifically, the materials targeted are metal−organic materials with desirable structural features and functional properties. Metal−organic materials are constructed from organic linker molecules and metal ions under relatively mild solvothermal reaction conditions that preserve the structural features of the relatively simple building blocks. Therefore, it is feasible to conceive a retrospective pathway of the reaction and thus deconstruct the desirable structures into simple, chemicallyrelevant, building blocks in an approach known as the molecular building block approach. Due …

Functionalization Of Resorcinarenes And Study Of Antimicrobial Activity, Kirankirti Muppalla

USF Tampa Graduate Theses and Dissertations

Cavitands are very important class of compounds in supramolecular chemistry. These molecules contain rigid enforced cavity,and have attracted considerable attention in supramolecular chemistry as building blocks for the construction of carcerands, hemicarcerands, and other host guests complexes. Nearly 40 years ago, Niederl and Vogel laid foundation for the study of such type of condensation reactions. In our laboratory we are involved in synthesis of resorcinarenes with readily available substrates such as resorcinol and aldehydes to form a cyclic tetramer.

Herein, I present detailed studies about the functionalization of the synthesized tetramers and their antimicrobial activity. Octahydroxy resorcinarenes were synthesized and …

An Investigation Into The Antifungal Activities Of N-Thiolated Beta- Lactams Against Selected Candida Species, Marci Culbreath

USF Tampa Graduate Theses and Dissertations

β-lactam antibiotics have long been a reliable course of treatment for bacterial infections. However, with recent increases in resistance and rising populations of immunocompromised patients new β-lactams have been synthesized and tested. The Turos laboratory has recently discovered novel β-lactams that have a mode of action distinct from penicillin and other β-lactam antibiotics as cell lysis is not observed. In the current investigations, these compounds are shown to also have antifungal properties. The rising incidence and prevalence of invasive fungal infections has become an increasing concern. The most common fungal pathogens involved in these infections are species in the genus …

Chemo-Enzymatic Route To Synthesis Of Biodegradable Polymers And Glycolipid Analogs, Surbhi Bhatt

USF Tampa Graduate Theses and Dissertations

New catalytic synthetic methods in organic chemistry that satisfy increasingly stringent environmental constraints are in great demand by the pharmaceutical and chemical industries. Studies over last 15 years have revealed that activity of enzymes can be increased in organic solvents rather than their natural aqueous environment. Because of their ease of use, high selectivity and environment friendliness, enzymes are enjoying increasing popularity in today's synthesis world.

Chapter 1 describes chemo-enzymatic synthesis of various glycolipid analogs. A highly regioselective macrolactonization was achieved using lipase from Candida antarctica as a catalyst. It also describes evaluation of lipases from different source and their …

The Growth And Toxicity Of The Florida Red Tide Organism, Gymnodinium Breve, Marion Tilton Doig Iii

USF Tampa Graduate Theses and Dissertations

Mass mortalities of marine organisms in the Gulf of Mexico have been associated with blooms of the unarmored dinoflagellate, Gymnodinium breve. This investigation concerns the factors affecting the growth of G. breve and the properties of a toxin produced by the organism.

A modification of the Flask Test of the Provisional Algal Assay Procedure of the Joint Industry/Government Task Force on Eutrophication was used to determine the response of G. breve to various natural waters and enrichments. The growth-promoting potential of natural waters obtained from areas where outbreaks of G. breve frequently occur was greater than that of waters …