Chemistry Commons^™

One-Step Synthesis Of Kanamycin Functionalized Gold Nanoparticles With Potent Antibacterial Activity Against Resistant Bacterial Strains, Hitesh Kumar Waghwani

Masters Theses & Specialist Projects

On the verge of entering the post-antibiotic era, numerous efforts are in place to regain the losing potential of antibiotics which are proving ineffective against common bacterial infections. Engineered nanomaterials, especially gold nanoparticles (GNPs) capped with antibacterial agents are proving to be an effective and novel strategy against multi-drug resistant (MDR) bacteria. In this study, we report a one-step synthesis of kanamycin-capped GNPs (20 ± 5 nm) utilizing the combined reducing and capping ability of the aminoglycoside antibiotic, kanamycin. Antibacterial assays showed dosedependent broad spectrum activity of Kan-GNPs against Gram-positive (Staphylococcus epidermidis and Enterococcus durans), Gram-negative (Escherichia coli and Enterobacter …

Thiophene And Derivatives For Use In Pyridazines And Thiapentalenes, Benjamin Tyree Cannon

Masters Theses & Specialist Projects

This thesis introduces the idea of Band Theory and how it can be used to describe a solid-state materials ability to carry an electrical charge. Next, this thesis defines what makes a material a conductor, semiconductor, or insulator. Semiconductors are attracting interest in chemistry, as well as in the manufacturing of consumer electronics, because of their ability to carry a charge, without the risk of short-circuiting like traditional conductors.1,4 Organic semiconductors, which behave differently than traditional semiconductors, are of particular interest because they offer mechanical flexibility, lowcost, simplicity, and the ability to be manufactures at low temperatures.6 Nonorganic and organic …

Green Chemistry As A Tool For Understanding The Toxic Substances Control Act: A Lecture Module For Undergraduate Students, Molly R. Blessing

Honors Scholar Theses

The Toxic Substances Control Act (TSCA) is the central form of chemical regulation existent in the United States today, yet scientists are often unaware or uncertain of its provisions. Violations of TSCA by unknowing chemists set industry and government unnecessarily at odds. A lecture on TSCA was developed for undergraduate students that uses the concept of green chemistry to promote interest and incentivize learning. Green chemistry methods are cleaner and less wasteful than traditional chemical ones, and many companies using them are at the forefront of technological innovation. The lecture explains both green chemistry and TSCA, includes company case studies, …

Novel [3,3]- And [1,3]- Rearrangements Of Azole-Derived N,X-Ketene Acetals, Sefat A. Alwarsh

Graduate Theses and Dissertations

The formation of carbon-carbon bonds in organic chemistry is fundamentally important. One of the major reactions that chemists have widely investigated is the Claisen rearrangement. Based on the fundamental features of this rearrangement, chemists exploited the capability of the transformation and invented their own variations of Claisen-type rearrangements. Our goal in this project is to develop a novel variation of the Claisen rearrangement using azole compounds, which are common heteroaromatic ring systems that are present extensively in the biomedically important natural products. We propose here novel methodologies of preparing 2-substitution azole derivatives using aza-based Claisen rearrangement, N,X-ketene acetals that requires …

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

Honors Scholar Theses

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.

Characterization Of Cellulase Enzyme Inhibitors Formed During The Chemical Pretreatments Of Rice Straw, Kalavathy Rajan

Graduate Theses and Dissertations

Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning …

The 8-Silyloxyquinoline Scaffold As A Versatile Platform For The Sensitive Detection Of Aqueous Fluoride, Xinqi Zhou

Department of Chemistry: Dissertations, Theses, and Student Research

As one of the most essential elements in nature, fluoride has been well known and extensively studied since the 16^th century. Since then the two-edged nature of fluoride in biological systems has been well described. Specifically, moderate fluoride exposure can aid in tooth and bone development, while fluoride overexposure results in the depilating disease known as fluorosis. Because of the side effects upon overexposure of fluoride, there is a need to develop fast and straight forward methods to sensitively and selectively detect and quantify fluoride concentration in drinking water. With this goal in mind and by taking advantage of …

Synthesis Of Β-Triphosphotriester Pronucleotides, Yousef Beni, Chandravanu Dash, Keykavous Parang

Chemistry Faculty Research

Dinucleoside phosphorochloridite was synthesized from phosphorus trichloride and three nucleoside analogs, 3′-fluoro-2′,3′-dideoxythymidine (FLT), 2′,3′-dideoxy-5-fluoro-3′-thiacytidine (FTC), and 2′,3′-dideoxy-3′-thiacytidine (3TC), in a multistep synthesis. Polymer-bound N-Boc p-acetoxybenzyl 5′-O-2′-deoxythymidine was reacted with dinucleoside phosphorochloridite in the presence of 2,6-lutidine, followed by the reaction with dodecyl alcohol and 5-(ethylthio)-1H-tetrazole, oxidation with tert-butyl hydroperoxide, and acidic cleavage, respectively, to afford the β-triphosphotriester derivatives containing three different nucleosides.

Novel Photodynamic Therapy Agents: Biochemical Analysis, Eboni D. Pullen

Honors College Theses

Bioinorganic photochemistry is a rapidly advancing research area in the field of bioinorganic chemistry. This project seeks to build upon the growing field by synthesizing and analyzing new photodynamic therapy (PDT) agents. There are three major generations of PDT agents. The first generation consists of chemically modified natural hematoporphyrins, which are not of great interest in the phototherapeutic field due to their low distinguishability between tumor cells and healthy cells, and extended skin photosensitivity in patients. The second generation consists of organic dyes, aromatic hydrocarbons, polypyrolics complexes, and semi-conductors, but is also not of much interest due to the same …

The Phytotoxic Virulence Factor Bcsnod 1 From Botrytis Cinerea, Gnana Sreekar Nidadavolu, Hana Mcfeeters

Research Horizons Day Posters

No abstract provided.

Synthesis And Characterization Study Of Biomimetic Tetradentate Ni Complexes, Nirupama Singh

Research Horizons Day Posters

No abstract provided.

Active Site Mimics Of Nickel Superoxide Dismutase, Victoria Grace Snider

Research Horizons Day Posters

No abstract provided.

High Mannose Binding Lectins - A New Class Of Attractive Antifungals, Tyler Hays Jones

Research Horizons Day Posters

No abstract provided.

Non-Covalent Affinity Materials For Protein Structure Determination Via Single Particle Reconstruction Analysis Cryo-Electron Microscopy, Minji Ha

Open Access Theses

Single particle analysis (SPA) by cryogenic electron microscopy (Cryo-EM) is one of the powerful tools for determining biological macromolecule structure, particularly when combined with computational methods or X-ray crystallography. However, the SPA is challenged by sample processing efficiency. In this work, polyrotaxane (PRTx) was designed and synthesized such that laterally and rotationally mobile lysine nitrolicacetic acid (Lys-NTA) modified α-cyclodextrins (α-CD) were threaded onto a polyethylene glycol (PEG) core. Polyrotaxanes threaded with amine modified α-CD were also designed and synthesized for stoichiometric control of His-tagged protein capture by PRTx. For higher efficiency of single particle analysis along a single strand of …

A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li

Open Access Theses

Proton affinity (PA) is a fundamental property that is related to the structure and reactivity of a molecule. Currently, very few experimental PA values are available for organic radicals and none for biradicals. Equilibrium methods cannot be used for these measurements. The traditional bracketing method is based on monitoring reactions of different reference bases with known proton affinities with the protonated analyte for the occurrence of exothermic proton transfer to determine the upper and lower limits of proton affinity. However, the energy deposited into the precursor ions upon CAD when forming protonated radicals may cause endothermic proton transfer reactions occur …

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard

Open Access Dissertations

The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been shown to act as the primary driver for these chemical depletions, although both chlorine and iodine atoms also contribute. Molecular bromine, along with its oxidation products, have been well studied in the Arctic, yet chlorine has not. Chlorine is known to impact the local oxidation capacity via its high reactivity with volatile organic compounds. Despite …

Comprehensive Organic Synthesis Ii (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Jeffrey Glans' review focuses on the online version available through ScienceDirect.

Knochel, Paul and Gary A. Molander, eds. Comprehensive Organic Synthesis II. 2nd ed. Amsterdam; Waltham, MA: Elsevier, 2014. Web.

http://www.sciencedirect.com/science/referenceworks/9780080977430

ISBN: 9780080977430 (e-book)

New Methods For Synthesis Of Organic Peroxides And Application Of Peroxide Electrophiles To Synthesis Of Functionalized Ethers, Shiva Kumar Kyasa

Department of Chemistry: Dissertations, Theses, and Student Research

New Method for Synthesis of Alkyl Hydroperoxides: There are a number of methods reported for synthesis of alkyl hydroperoxides, but most of them suffer either from poor yields or the formation of unwanted side products. I will be discussing new methodology for efficient synthesis of pure samples of 1° and 2° alkyl hydroperoxides via alkylation of readily available cyclododecanone 1,1-dihydroperoxide followed by hydrolysis of the resulting bis peroxyacetals.

Peroxide Electrophiles for Synthesis of Functionalized Ethers: Peroxides are underexplored functional groups as precursors for C-O bond formation and ether synthesis. The reactivity of dialkyl peroxides towards organometallics such as alkyl lithium …

Toward Electronic Materials Based On Metal Pincer-Type Complexes, Jeewantha Sampath Hewage

Master's Theses (2009 -)

There is currently a lot of interest in developing electrically conducting or semiconducting metal-organic frameworks (MOF's), highly porous materials constructed by organic ligands bridging metal centers. Typically MOF's are non-conducting and, moreover, they are susceptible to hydrolytic degradation. If hydrolytically stable and electrically conducting MOFs could be realized, then revolutionary new technologies could be envisioned. Currently, organic dicarboxylates are used as bridging organic ligands and one simple strategy to obtain the desired materials is to explore other ligand systems. Pincer ligands are organic compounds that are uninegative and bind metals in a tridentate, meridional fashion with two five-member chelate rings. …

Violacein Induces P44/42 Mitogen-Activated Protein Kinase‑Mediated Solid Tumor Cell Death And Inhibits Tumor Cell Migration, Toral Mehta, Koen P. Vercruysse, Terrance Johnson, Anthony Okechukwu Ejiofor, Elbert Myles, Quincy A. Quick

Chemistry Faculty Research

Microbial secondary metabolites have emerged as alternative novel drugs for the treatment of human cancers. Violacein, a purple pigment produced by Chromobacterium violaceum, was investigated in the present study for its anti‑tumor properties in tumor cell lines. Clinically applicable concentrations of violacein were demonstrated to inhibit the proliferative capacity of tumor cell lines according to a crystal violet proliferation assay. The underlying mechanism was the promotion of apoptotic cell death, as indicated by poly(ADP ribose) polymerase cleavage and p44/42 mitogen‑activated protein kinase signaling determined by western blot analysis. Collectively, this provided mechanistic evidence that violacein elicits extracellular-signal regulated kinase‑induced apoptosis …

The Detection And Quantitative Analysis Of Endocannabinoids And Endogenous Fatty Acid Amides In Apis Mellifera And Tribolium Castaneum, Perry Robert Mitchell Jr.

USF Tampa Graduate Theses and Dissertations

Endocannabinoids, and the fatty acid amides from which they are a member, have garnered greater scientific interest in the last two decades due to the cannabimimetic properties of these endogenous molecules. The most well-known of these is Anandamide, which has thus far been discovered in several species of animal ranging from C. elegans, fruit flies, to bovine and humans. Because of the importance and increasing impact of these compounds a brief overview is first presented herein, with a major focus on the N-acyldopamines due to the direct impact they potentially pose to human physiology.

Secondly, the detection and …

Gamma-Aapeptides As A New Class Of Peptidomimetics: Synthesis, Structures, And Functions, Haifan Wu

USF Tampa Graduate Theses and Dissertations

Peptidomimetics are synthetic oligomers that resemble the activities of peptides. Their advantages over peptides include high stability towards proteolysis and enormous chemical diversity. Over the past two decades, there have been extensive efforts to develop peptide mimics, such as beta-peptides, peptoids, D-peptides, etc. The research on peptidomimetics have led to many important applications in both medicinal and material science. In order to explore new functions, the discovery of peptidomimetics with novel frameworks is essential. We reported the synthesis and evaluation of a new class of peptidomimetics, termed as gamma-AApeptides. Previous studies of gamma-AApeptides have revealed that gamma-AApeptides are highly resistant …

Design And Synthesis Of Bioactive Peptidomimetics, Yaogang Hu

USF Tampa Graduate Theses and Dissertations

Protein-Protein Interactions (PPIs) play a very important role in biological functions and therefore the inhibition of specific Protein-Protein Interactions has a huge therapeutic value. The most successful small molecular PPIs inhibitors do not fit with the prevalent `Rule of Five' drug profile. To overcome the disadvantages of small molecular PPIs inhibitors, peptide based PPIs inhibitors were developed. Herein we describe the development of a new class of peptidomimetics AA-peptides. The AApeptides were designed based on chiral PNA backbone. Substitution of nucleobases yields AApeptides that are resistant to proteolysis and capable of mimicking peptides. Two types of AApeptides were discussed in …

Towards The Total Synthesis Of (+/-)-Gephyrotoxin 287c, Maciej E. Domaradzki

Dissertations, Theses, and Capstone Projects

Studies directed toward the total synthesis of (+/-)-Gephyrotoxin 287C are described herein. Even though the target alkaloid has been synthesized four times to date, it still presents an interesting synthetic challenge. Our ultimate goal is to develop an efficient enantioselective synthetic route utilizing oxazolone chemistry in order to demonstrate its utility as a dienophilic component in intramolecular Diels-Alder reactions. This is part of a greater ongoing study aimed at a range of suitable alkaloid targets.

Chapter 1 provides introduction to frog toxins as secondary metabolites and subsequently shifts to the target alkaloid. (+/-)-Gephyrotoxin 287C was originally described by Daly and …

Synthesis Of Dinucleoside Acylphosphonites By Phosphonodiamidite Chemistry And Investigation Of Phosphorus Epimerization, William H. Hersh

Publications and Research

The reaction of the diamidite, (iPr2N)2PH, with acyl chlorides proceeds with the loss of HCl to give the corresponding acyl diamidites, RC(O)P(N(iPr)2)2 (R = Me (7), Ph (9)), without the intervention of sodium to give a phosphorus anion. The structure of 9 was confirmed by single-crystal X-ray diffraction. The coupling of the diamidites 7 and 9 with 5′-O-DMTr-thymidine was carried out with N-methylimidazolium triflate as the activator to give the monoamidites 3′-O-(P(N(iPr)2)C(O)R)-5′-O-DMTr-thymidine, and further coupling with 3′-O-(tert-butyldimethylsilyl)thymidine was carried out with activation by pyridinium trifluoroacetate/Nmethylimidazole. The new dinucleoside acylphosphonites could be further oxidized, hydrolyzed to the H-phosphonates, and sulfurized to …

Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati Nigudkar, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

Recent developments in stereoselective 1,2-cis glycosylation that have emerged during the past decade are surveyed herein. For detailed coverage of the previous achievements in the field the reader is referred to our earlier reviews: A. V. Demchenko, Curr. Org. Chem., 2003, 7, 35–79 and Synlett, 2003, 1225–1240.

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …

Scale Up Isolation Of Aaptamine For In Vivo Evaluation Indicates Its Neurobiological Activity Is Linked To The Delta Opioid Receptor, Nicole L. Mcintosh, Eptisam Lambu, Laura Millan-Lobo, Fei Li, Li He, Phillip Crews, Jennifer L. Whistler, Tyler Johnson

Student Research Posters

Opioid receptors belong to the large superfamily of seven transmembrane-spanning (7TM) G protein-coupled receptors (GPCRs). As a class, GPCRs are of fundamental physiological importance mediating the actions of the majority of known neurotransmitters and hormones. The Mu, Delta, and Kappa (MOP, DOP, KOP) opioid receptors are particularly intriguing members of this receptor family as they are the targets involved in many neurobiological diseases such as addiction, pain, stress, anxiety, and depression. Recently we discovered that the aaptamine class of marine sponge derived natural products exhibit selective agonist activity in vitro for the DOP versus MOP receptor. Our findings may explain …

Efficient Utilization Of Solar Energy In Dye-Sensitized Solar Cells And In The Photocatalytic Reduction Of Carbon Dioxide, Aron Joel Huckaba

Electronic Theses and Dissertations

One of the most important questions humanity will face in the next 100 years is going to be "What will happen when oil runs out?" This dissertation describes efforts to utilize solar energy to improve renewable energy technology in two ways: First, through the improvement of dye sensitized solar cells by theimprovement of D-π-A dye subunits, the development of practical sensitizers, and progress towards stable, tunable redox shuttles. A novel indolizine donor subunit was synthesized that was shown to be the strongest reported donor. Dyes made from this novel donor and devices using the Γ-/I 3- reached up to 5.4% …

Methods Of Analysis For Fermentation Science Products Using Various Analytical Techniques, Casey Jay Howdieshell

Online Theses and Dissertations

Fermentation science, the study of microorganisms as they digest food sources to produce usable products for consumption, has been around since the dawn of modern civilization. Historically, the fermentation process has been utilized for the production of alcoholic beverages. More recently, however, the production of bioethanol and biodiesel as a fuel source alternative to classical fossil fuels has gained increased popularity. As with any synthetic process, derivations and optimizations for ideal production are needed. As such, analytical techniques must be implemented to ensure quality control and pinnacle efficiency. This body of work describes analytical techniques providing key qualitative and quantitative …