Chemistry Commons^™

Photopolymerization Synthesis Of Magnetic Nanoparticle Embedded Nanogels For Targeted Biotherapeutic Delivery, Daniel Jonwal Denmark

USF Tampa Graduate Theses and Dissertations

Conventional therapeutic techniques treat the patient by delivering a biotherapeutic to the entire body rather than the target tissue. In the case of chemotherapy, the biotherapeutic is a drug that kills healthy and diseased cells indiscriminately which can lead to undesirable side effects. With targeted delivery, biotherapeutics can be delivered directly to the diseased tissue significantly reducing exposure to otherwise healthy tissue. Typical composite delivery devices are minimally composed of a stimuli responsive polymer, such as poly(N-isopropylacrylamide), allowing for triggered release when heated beyond approximately 32 °C, and magnetic nanoparticles which enable targeting as well as provide a mechanism for …

Germania- And Silica-Based Perfluorinated And Non-Fluorinated Sol-Gel Sorbents For Capillary Microextraction In Chromatographic Analysis, Emre Seyyal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most time-consuming and error-prone step in chemical analysis. Miniaturization and automation of the sample preparation equipment eliminating or reducing the use of hazardous organic solvents, online hyphenation of sample preparation with analytical instruments in a cost-effective way are important factors that need to be considered to design and implement innovative sample preparation techniques and strategies. Solid-phase microextraction (SPME) is a simple, environmentally benign technique well suited for hyphenation with analytical instruments. However, poor coating stability is a significant drawback of SPME employing conventionally prepared coatings. This shortcoming arises from the lack of chemical bonding between the …

Exploring Student Learning In Post-Secondary General Chemistry: Novel Tools For Measuring Linked Concepts And Study Habits, Li Ye

USF Tampa Graduate Theses and Dissertations

This dissertation presents novel tools to help instructors measure students linking of content knowledge and the actions students perform for studying in the context of post-secondary General Chemistry.

The first tool described in this work is Creative Exercises (CEs), an open-ended assessment that has the potential to promote students making connections across the content covered in General Chemistry. Students are given a simple prompt that describes a chemistry situation, and asked to write as many statements as they can that are correct, distinct and relevant to the prompt and the course content. The written responses to CEs from both in-class …

On The Conformational Dynamics Of Dna: A Perspective From Molecular Dynamics Simulations, Ning Ma

USF Tampa Graduate Theses and Dissertations

The main focus of my dissertation is on the conformational motion of DNA, studied by applying tools from the computational chemistry field. In addition, studies of relative α- and 310 helical stabilities in peptides/mini-proteins, and a molecular flooding study of the retinoid X-receptor as part of a continuing drug design effort are presented. In molecular biology, it has been well known that sequence determines structure, and structure controls function. For proteins or DNA to work properly, the correct configuration is required. Mutations may alter the structure, which can cause malfunction. Non-mutational effects, such as a change in environment may also …

Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti

USF Tampa Graduate Theses and Dissertations

Differential Mobility Spectrometry (DMS) using a non-radioactive ion source (NRIS) is investigated as a possible medical diagnostic instrument for near real-time detection of breast cancer biomarkers. In previous clinical studies, concentrations of Linoleic, Palmitic and Stearic fatty acids have been observed at different levels in women with carcinoma breast cancer versus women with benign tumors or healthy women showing no signs of breast cancer. Present diagnostic methods require a biopsy of the suspect tissue and a microscopic lab analysis performed to determine its disease state. This process can take hours or days before the patient and doctor are informed of …

New Reaction Discoveries In Gold Catalysis, Seyedmorteza Hosseyni

USF Tampa Graduate Theses and Dissertations

In this dissertation, gold catalyst was employed to catalyze intermolecular reactions. Intramolecular reactions were far more advanced than intermolecular reaction in gold catalysis. With finding suitable ligands for gold catalysts, we were able to develop several transformations to synthesize interesting building blocks in organic chemistry including: allenes, furans, spiros, oxepines, propargyl ethers and ketones. These functionalities were synthesized by the use of triazole-gold(I) catalyst. Triazole, as a ligand bond to gold, showed enhanced stability of the catalyst, which resulted in better yields. Gold(I)/(III) redox chemistry also used for cyclopropanol ring openings which resulted in synthesizing substituted ketones.

Hydroalkynylation Of Oxocarbenium Intermediates Via Au(I) Catalysis, Courtney Smith Smith

USF Tampa Graduate Theses and Dissertations

Au(I) catalysis has recently emerged as a powerful tool for the realization of a broad range of organic transformations. Despite this rapid development, attaining selectivity and maintaining catalyst stability remain significant challenges. Rational ligand design, such as the employment of NHC or TA ligands, has been used to confront these issues. This thesis focuses on the use of Au(I) catalysts bearing these ligands for the selective hydroalkynylation of enol ethers. By employing a TA-Au stabilized catalyst, [(OAr)₃PAu(TA-H)]OTf, the intermolecular hydroalkynylation of enol ethers, a substrate that is well-known to promote decomposition of the gold cation, was efficiently achieved. …

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO₂ photocatalysts for splitting water (4) and reducing CO₂ (5) to form useful chemical feedstock such as H₂, CO and CH₄, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …

Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most error-prone step in chemical analysis. A great deal of efforts has been made to develop efficient techniques and protocols for sample preparation to accomplish important goals such as miniaturization and implementation of green analytical methodologies. Solid-phase microextraction (SPME) has successfully eliminated the use of hazardous organic solvents in extraction sampling, sample preparation, preconcentration and sample introduction to the analytical instrument in an effective manner. Ensuring thermal- and solvent-instability of traditional SPME extraction phases represented one of their main drawbacks. This was solved by the introduction of sol-gel SPME phases characterized by enhanced thermal-, solvent-, and …

Synthesis And Characterization Of Novel Polyurethanes And Polyimides, Kenneth Kull

USF Tampa Graduate Theses and Dissertations

Four novel high performance soft thermoplastic polyurethane elastomers utilizing methylene bis(4-cyclohexylisocyanate) as a hard segment, 1,4 butanediol as a chain extender and modified low crystallinity carbonate copolymer as a soft segment were synthesized. The samples were characterized by infrared spectroscopy (FTIR), tensile, elongation, hardness, abrasion resistance and atomic force microscopy (AFM). SAXS data shows evidence of an interdomain "center-to-center" distance of 45Å. DSC traces show evidence of one glass transition temperature and a weak melting region. DMA analysis reveals a low temperature secondary relaxation and the glass to rubber transition followed by a rubbery plateau. All samples demonstrated the ability …

Metal-Organic Frameworks As Potential Platforms For Carbon Dioxide Capture And Chemical Transformation, Wenyang Gao

USF Tampa Graduate Theses and Dissertations

The anthropogenic carbon dioxide (CO₂) emission into the atmosphere, mainly through the combustion of fossil fuels, has resulted in a balance disturbance of the carbon cycle. Overwhelming scientific evidence proves that the escalating level of atmospheric CO₂ is deemed as the main culprit for global warming and climate change. It is thus imperative to develop viable CO₂ capture and sequestration (CCS) technologies to reduce CO₂ emissions, which is also essential to avoid the potential devastating effects in future. The drawbacks of energy-cost, corrosion and inefficiency for amine-based wet-scrubbing systems which are currently used in industry, …

Asymmetric Transformations Catalyzed By Chiral Binol Alkaline Earth Metal Phosphate Complexes, Sri Krishna Nimmagadda

USF Tampa Graduate Theses and Dissertations

Small molecule hydrogen bond donors have emerged as versatile catalysts in asymmetric synthesis. Within this class, chiral BINOL phosphoric acid is regarded as one of the pioneer catalysts used in several asymmetric transformations. The ability of the catalyst to activate the substrates could be controlled in two different ways. (1) Dual activation/bifunctional activation of substrate by hydrogen bond interactions or ion pairing with phosphoric acid or (2) By forming chiral BINOL phosphate metal complex that could significantly alter the interactions in chiral space. In particular, chiral alkaline earth metal phosphate complexes have unique advantages as catalysts owing to the ubiquitous …

Design And Development Of Peptidomimetic Ligands For Targeting Radiopharmaceuticals, Imaging Probes, And Immunotherapeutics In Oncologic Disease, Michael Lawrence Doligalski

USF Tampa Graduate Theses and Dissertations

Cancer is a leading cause of morbidity and mortality in the developed world. While much has been learned about these diseases in the last few decades, one of the main barriers to widespread advancement is the heterogeneity of cancer biology. A growing body of evidence supports the idea that certain protein receptors are overexpressed on the surface of tumor cells as compared to normal tissues. These extracellular biomarkers provide a unique opportunity to selectively target the tumor with both imaging and therapeutic modalities. The research in this dissertation focuses on targeting proteins on the tumor cell surface with peptidomimetic ligands. …

Applications Of Molecular Modelling And Structure Based Drug Design In Drug Discovery, Sreya Mukherjee

USF Tampa Graduate Theses and Dissertations

Calcium ions have important roles in cellular processes including intracellular signaling, protein folding, enzyme activation and initiation of programmed cell death. Cells maintain low levels of calcium in their cytosol in order to regulate these processes. When activation of calcium-dependent processes is needed, cells can release calcium stored in the endoplasmic reticulum (ER) into the cytosol to initiate the processes. This can also initiate formation of plasma membrane channels that allow entry of additional calcium from the extracellular milieu. The change in calcium levels is referred to as calcium flux. A key protein involved in initiation of calcium flux is …

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

Spatially Directional Resorcin[4]Arene Cavitand Glycoconjugates For Organic Catalysis In Aqueous Media, Ali Husain Husain

USF Tampa Graduate Theses and Dissertations

Resorcin[4]arenes and their rigid structures “cavitands” offer a unique molecular structure scaffolds suitable for attaching and orienting multi-ligands on their upper rims. Their remarkable structure properties, the relative ease of chemical modification on their either rims or through the multiple phenolic hydroxyl (-OH) groups, manipulating their cavity size and the role of spatial directionality provided by their cores, led synthetic chemist to explore their utilities in the synthesis of valuable resorcin[4]arene/cavitand assemblies with wide range of applications in many research areas such as supramolecular chemistry, host-guest chemistry, glycoconjugates, polymer chemistry, host-guest chemistry, micro-reactors in chemical catalysis and others. In particular, …

Gamma Aapeptides As Host Defense Peptide Mimics, Yaqiong Li

USF Tampa Graduate Theses and Dissertations

There has been increasing concern regarding the emergence of multi-drug resistant pathogens. The resistance develops when pathogens, especially bacteria, are frequently exposed to conventional antibiotics, as they are heavily used in both human and livestock. This is due to the high target specificity of conventional antibiotics, which places pathogens in high selective pressures and eventually results in drug resistant by mutations. To address this issue, global actions and cooperation are needed. At the same time, new technologies and strategies need to be developed. Host defense peptides (HDPs) are widely found in the innate immune system. They show both direct antimicrobial …

Chiral Boro-Phosphates In Asymmetric Catalysis: 1,4-Reduction Of Enones And Reductive Aldol, Susana Sorina Lopez

USF Tampa Graduate Theses and Dissertations

The biological activity of the pharmaceutical drugs often depends on how it fits with a receptor making stereochemistry a key component. Selective reactions can limit or avoid the mixture of enantiomers obtained. One such reaction is the selective reduction of a carbon-carbon double bond in the presence of a carbonyl. Although efficient, current asymmetric synthesis methods have limitations such as harsh reaction conditions, the high costs of chiral catalysts and the toxicity of the metal-based catalysts. Catalysts derived from small organic molecules have become an attractive alternative which have been explored more rigorously in recent years. Using a BINOL-derived boro-phosphate …

The Use Of Synthetic Mixture Based Libraries To Identify Hit Compounds For Eskape Pathogens, Leishmaniasis, And Inhibitors Of Palmitoylation, Marcello Giulianotti

USF Tampa Graduate Theses and Dissertations

The goal of this work is to demonstrate the utility of using systematically formatted mixture based libraries as part of the drug discovery processes. While there are a number of different valid approaches for identifying hit and tool compounds, systematically formatted mixture based libraries, such as those described in this study, offer the ability to develop a significant amount of structure activity relationship data from the testing of very few samples. In support of this claim a review of recent developments in the area of systematically formatted mixture based libraries as well as three case studies are presented. The three …

Co(Ii)-Based Metalloradical Catalysis For Asymmetric Radical Cyclopropanation, Qigan Cheng

USF Tampa Graduate Theses and Dissertations

Metal-catalyzed cyclopropanation of olefins with diazo reagents is one of the most general and efficient method to prepare cyclopropanes. The resulting cyclopropyl units are found as a basic structural element in a wide range of naturally occurring compounds and biologically active compounds, and can serve as versatile synthetic intermediates in the synthesis of multifunctionalized cycloalkanes and acyclic compounds. Since Co(II) complexes of D₂-symmetric chiral amidoporphyrins [Co(D₂-Por*)] were first introduced in 2004, Co(II)-metalloradical catalysis (MRC) have emerged as a new platform for asymmetric cyclopropanation. These metalloradical catalysts have been shown to be highly effective for asymmetric intermolecular …

Optimizing Protocols For Carbohydrate Nmr Chemical Shift Computations, Michael Trent Kemp

USF Tampa Graduate Theses and Dissertations

The spectroscopic analysis of cellulose is experimentally challenging while computationally accessible with recent developments in NMR code. However, prior to using density functional theory to calculate the NMR chemical shifts of cellulose, smaller, sugar-like molecule systems need to be benchmarked against experimental values. The quantum mechanical / molecular mechanical (QM/MM) calculations presented herein utilize six test systems: ethanol, pyridine, pyrrolidine, pyrrole, myo-inositol and scyllo-inositol in conjunction with the reference tetramethylsilane used to scale the calculated isotropic shielding tensors to relative chemical shifts. The effect of solvent on calculated NMR chemical shifts has also been investigated with regard to quantity of …

Modified Yttrium Hydroxide/Mc Nylon Nanocomposites And Scaling Effects In Multilayer Polyethylene Films, Jia Chen

USF Tampa Graduate Theses and Dissertations

In this thesis, monomer casting (MC) nylon was synthesized. MC nylon could replace nonferrous metals in certain applications, including gears, wheels, and other moving parts. However, compared with metals, MC nylon products have poor strength and stiffness, and crack easily, especially at low temperatures. In addition, the dimensional stability of MC nylon is poor, especially in the large casting nylon products, causing significant internal stresses due to shrinkage. Thus, MC nylon cracks easily when cast and molded. The yttrium hydroxide particles were modified by stearic acid and dispersed in the caprolactam. The polymerization time was short due to fast anionic …

Enhancement Of Supercapacitor Energy Storage By Leakage Reduction And Electrode Modification, Tete Tevi

USF Tampa Graduate Theses and Dissertations

Supercapacitors have emerged in recent years as a promising energy storage technology. The main mechanism of energy storage is based on electrostatic separation of charges in a region at the electrode-electrolyte interface called double layer. Various electrode materials including carbon and conducting polymers have been used in supercapacitors. Also, supercapacitors offer high life cycle and high power density among electrochemical energy storage devices. Despite their interesting features, supercapacitors present some disadvantages that limit their competitivity with other storage devices in some applications. One of those drawbacks is high self-discharge or leakage. The leakage occurs when electrons cross the double layer …

Chemical Investigation Of Antarctic Marine Organisms & Their Role In Modern Drug Discovery, Jacqueline Lee Fries

USF Tampa Graduate Theses and Dissertations

The chemicals produced by biological systems, whether proteins, peptides, or terpenes, will always provide an intriguing topic for researchers. Invisibly controlling every aspect of nature, these molecules are responsible for life, evolution, and death. Specifically, here is described the secondary metabolites produced by Antarctic marine organisms as well as others, and how they are used to defend or attract other animals while potentially providing health benefits to mankind. This is done through collection, extraction, and separation of individual specimens. The respective mixtures of compounds after isolation are then analyzed via spectroscopic methods such as nuclear magnetic resonance spectroscopy, mass spectrometry, …

Design, Synthesis And Screening Of Peptidomimetics For Anticancer And Antiviral Drug Candidates, Yi Liang

USF Tampa Graduate Theses and Dissertations

The high demand of novel peptide and peptidomimetics based on the amount of genomic and proteomic data need be matched by synthesis and screening. The design and synthesis of peptide and peptidomimetics are so important because the peptide and protein-protein interaction play a key role in molecule recognition and signaling. The modified peptides have better stability and pharmacokinetic properties which may be guided by rational design and molecular modeling. Now many organic and medicinal chemists have chosen peptide and peptidomimetics as potential drug candidates for many targets.

In this dissertation, research efforts in design and synthesis of cyclic peptides with …

Synthesis Of Agents For The Treatment And Analysis Of Tropical Diseases, Jeanine Yacoub

USF Tampa Graduate Theses and Dissertations

Toxoplasmosis is an opportunistic disease caused by the protozoan parasite Toxoplasma gondii. The parasite is usually staved off by a healthy immune system and remains dormant in the body. In immunocompromised patients, the parasite can become active and spread throughout the body causing symptoms such as encephalitis, cognitive disorders, seizures, and death. Combination drug therapy is the usual treatment for toxoplasmosis; however, patients suffer from problems of intolerance, allergic reactions, and cytotoxicity. In an effort to identify new drug targets for toxoplasmosis, a series of compounds have been synthesized that can be used as tools to probe the unique …

Investigation Of Low Thermal Conductivity Materials With Potential For Thermoelectric Applications, Kaya Wei

USF Tampa Graduate Theses and Dissertations

Thermoelectric devices make it possible for direct energy conversion between heat and electricity. In order to achieve a high energy conversion efficiency, materials with a high thermoelectric figure of merit (ZT = S²σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity) are in great demand. The standard approach is to optimize charge carrier transport while at the same time scatter the heat transport, a task that is easier said than done. Improving the electrical properties in order to increase ZT is limited since electrons …

Novel Enzyme Perspectives: Arylalkylamine N-Acyltransferases From Bombyx Mori & 1-Deoxy- D-Xylulose-5-Phosphate Synthase From Plasmodium Falciparum And Plasmodium Vivax, Matthew R. Battistini

USF Tampa Graduate Theses and Dissertations

This dissertation is dedicated to the research and investigation of novel enzymes and the methods used to study them, with physiological roles ranging from isoprenoid biosynthesis to neurotransmitter production. Using a combination of bioinformatics, recombinant cloning, enzymology, and proteomics, we have contributed to the understanding and exploration of several human illnesses, including malaria, cancer, and endocrine dysfunction.

Our first project involved studying the enzymes responsible for N-acylarylalkylamide biosynthesis in Bombyx mori. Very little is known how these potent signaling molecules are produced in vivo, however, one possible pathway is the direct conjugation of an acyl-CoA to a corresponding …

Tailoring The Pore Environment Of Metal-Organic And Molecular Materials Decorated With Inorganic Anions: Platforms For Highly Selective Carbon Capture, Patrick Stephen Nugent

USF Tampa Graduate Theses and Dissertations

Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO₂ because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible …

Photoacoustic Calorimetry Studies Of The Earliest Events In Horse Heart Cytochrome-C Folding, Tarah A. Word

USF Tampa Graduate Theses and Dissertations

The protein folding problem involves understanding how the tertiary structure of a protein is related to its primary structure. Hence, understanding the thermodynamics associated with the rate-limiting steps for the formation of the earliest events in folding is most crucial to understanding how proteins adopt native secondary and tertiary structures. In order to elucidate the mechanism and pattern of protein folding, an extensively studied protein, Cytochrome-c (Cc), was chosen as a folding system to obtain detailed time-resolved thermodynamic profiles for the earliest events in the protein folding process. Cytochrome-c is an ideal system for understanding the folding process for several …