Chemistry Commons^™

Chemical Investigation Of Avocado (Persea Americana) Seed Husk (Testa): A Waste Of Waste, Orlando A. Castillo Scheren

Theses and Dissertations

Food chemistry is a new field in the world and is currently still expanding into the types of market in which it can be tapped into. There are about 1.3 billion tons of food waste produced in 2016 in the world, and food chemistry is going to help get rid of that waste by finding new and exciting applications to the things currently considered as waste. In these products, there might be new and undiscovered drugs that can be used in the market to help treat diseases for which might not have a cure at the current moment. The avocado …

Synthesis, Characterization, And Application Of Meso-Tetraphenyl Metalloporphyrin Photocatalysts Under Visible Light, Alexis Echavarria

Theses and Dissertations

The photocatalytic activity of meso-Tetraphenyl Metalloporphyrins with different metal centers was investigated. The synthesized metalloporphyrin photocatalysts was performed and analyzed using FT-IR spectroscopy, UV-VIS spectroscopy, and powder X-Ray Diffraction analysis. The synthesized TPP crystals were determined to be tetragonal crystal structure and the structure was observed in all synthesized metalloporphyrin catalysts. The Soret (B) bands, Q bands, FT-IR functional groups were identified. Reaction progress was investigated by sampling at intervals of one hour and analysis of the samples was performed using Gas Chromatography-Mass Spectrometry. GC-MS analysis was used to identify the products of the photochemical catalytic redox reactions performed under …

Thermal And Spectroscopic Investigations On Polymer-Based Nanofibers, Omosola Oriretan

Theses and Dissertations

Nanofibers of Poly (ethylene oxide), PEO, Poly (vinylpyrrolidone) PVP, Co-nanofiber of PEO-PVP and PEO nanocomposite of various Fullerene compositions were prepared by dissolving PEO, PVP and Fullerene in water. The Fullerene nanoparticles were added to the PEO solutions, the mixtures were homogenized under high power sonication. The PEO solutions, PVP solutions, the co-polymer solutions of PEO-PVP and the PEO -Fullerene solutions were centrifugally spun using Force spinning™ machine. The obtained nanofibers and the nanocomposites were subjected to FTIR analysis, Raman analysis and various heating and cooling cycles with heating and cooling rates ranging from 10C/min to 600C/min using differential scanning …

Chemical Modification And In Silico Validation Of Medicinally Privileged Molecular Scaffolds As Kras And Sars-Cov-2 Protease Inhibitors, Precious M. Okwuchukwu

Theses and Dissertations

Coronavirus disease was declared a global pandemic by WHO in March 2020, cancer is the second leading cause of death by a disease. Several scientists around the world are working relentlessly to discover an effective remedy to eradicate these deadly diseases. A natural polyphenol (magnolol) has been isolated from a tree Magnolia grandiflora (family Magnoliaceae) found on UTRGV campuses. This research is focused on design of a series of chemically modified sulfonyl derivatives based on the isolated magnolol framework and other medicinally privileged molecular scaffolds framework that can effectively bind to the COVID-19 main protease, SARS- CoV-2 3CL protease …

Total Synthesis Of Cytotoxic Mansouramycins From Amino Acids, Beatriz Gamez

Theses and Dissertations

Natural products produced by plants, animals, and microorganisms are of significant importance in chemistry for being major sources of molecular scaffolds essential for new drug discovery. Mansouramycins are cytotoxic bioactive compounds containing isoquinoline skeletons with substituents on the quinone and pyridine rings that may be difficult to synthesize. Synthetic processes exist for compounds B and D, however, there exists an absence of simple synthetic approaches to all four alkaloids.

This project aims to provide a general total synthetic pathway to Mansouramycins A—D from amino acids for possible use in cancer treatment via these isoquinolinequinones. Preliminary experimentation suggests there may be …

Photoelectrical And Photoelectrochemical Characterization Of The Materials Used In Dye-Sensitized And Perovskite Solar Cells., Pom Lal Kharel

Electronic Theses and Dissertations

Solar energy is one of the most important alternative renewable energy sources to fulfill the increasing demand of energy in the world. Third-generation solar cells like dye-sensitized solar cells, perovskite solar cells, quantum dot solar cells, and organic solar cells are extensively studied to increase their photoconversion efficiency, and ultimately for their large-scale implementation. A dye-sensitized solar cell consists of a photoanode of a mesoporous film of titania sensitized with dye sandwiched with a counter electrode, which is usually a platinum-coated transparent conducting oxide, and a redox couple injected between the photoanode and counter electrode. Doping titania with rare-earth metal …

Alkylation Of Benzene On Immobilized Phosphotungstic Acid, Kofi Kankam

Electronic Theses and Dissertations

Linear alkylbenzenes (LAB) are key intermediates in the synthesis of linear alkylbenzene sulfonate surfactants that are used in the manufacture of detergents. Production of LAB with traditional Lewis acids as catalysts, such as hydrofluoric acid, results in the formation of large amounts of toxic wastes and corrosion of industrial equipment. Phosphotungstic acid (PTA) has gained much attention in recent years as a solid catalyst for various alkylation reactions. This research work aims to develop a novel material based on PTA-containing silica gel, which can effectively catalyze LAB synthesis. Sol-gel synthesis of silica gel in the presence of PTA and tetraethyl …

Polymer-Based Capacitive Gas Sensor For Machine Olfaction, Mohamed Fathy Hassan

Theses and Dissertations

Transferring human abilities and knowledge to machines has been the focus of decades of work by scientists and engineers. With the progress in computation power and algorithms such as artificial neural networks, machines have surpassed humans in complicated games like chess and the Chinese game Go. Some senses can be mimicked including touch, with pressure sensors, hearing, with microphones, and vision with charged couple device (CCD)imaging chips. Yet, relatively little progress has been made with the senses of smell and taste. Machine olfaction, the ability to detect and quantify vapors in the environment, poses a range of challenges, which if …

Strain Control Of Layer-Resolved Negative Capacitance In Superlattices, Raymond Walter, Sergey Prosandeev, Charles Paillard, L. Bellaiche

Physics Faculty Publications and Presentations

Negative capacitance in BaTiO₃/SrTiO₃ superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model, using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields. We show that epitaxial strain can tune the negative capacitance of the BaTiO₃ ferroelectric layer and the overall capacitance of the system. In addition, we predict and explain an original switching of the negative capacitance from the BaTiO₃ layer to the SrTiO₃ layer at low temperatures for intermediate strains.

Development Of Computational To Ols To Target Microrna, Luo Song

Dissertations and Theses (Open Access)

MicroRNAs (a.k.a, miRNAs) play an important role in disease development. However, few of their structures have been determined and structure-based computational methods remain challenging in accurately predicting their interactions with small molecules. To address this issue, my thesis is to develop integrated approaches to screening for novel inhibitors by targeting specific structure motifs in miRNAs. The project starts with implementing a tool to find potential miRNA targets with desired motifs. I combined both sequence information of miRNAs and known RNA structure data from Protein Data Bank (PDB) to predict the miRNA structure and identify the motif to target, then I …

Nuclear-Targeted Gold Nanoparticles Enhance The Effects Of Radiation Therapy With And Without Liposomal Delivery, Maureen Aliru

Dissertations and Theses (Open Access)

Less that 10% of pancreatic cancer patients are eligible for curative resection, and clinical trials evaluating chemoradiation in locally advanced patients with unresectable disease have been largely disappointing. New and creative therapeutic approaches are needed to address the unment need for treatment options. The objective of this thesis is to advance radiosensitization of treatment-resistant densely desmoplastic pancreatic cancer using nanoparticles to surmount biological barriers to effective particle distribution for DNA-targeting.

Clinical translation of radiosensitizing nanoparticles has stalled owing to technical challenges. Current strategies to use AuNPs for radiosensitization require large quantities of gold, kilovoltage x-rays, immediate irradiation after intravenous administration, …

Spatially Directed Functionalization By Co-Electropolymerization Of Two 3,4-Ethylenedioxythiophene Derivatives On Microelectrodes Within An Array, Benjamin J. Jones, Carol Korzeniewski, Jefferson H. Franco, Shelley D. Minteer, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

Electrodeposited conductive copolymer films with predictable relative properties (quantities of functional groups for further modification and capacitance) are of interest in sensors, organic electronic materials and energy applications. Potentiodynamic copolymerization of films in aqueous solutions of two different thiophene derivatives, (2,3-dihydrothieno[3,4-b]dioxin-2-yl) methanol (1) and 4-((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)-methoxy)-4-oxobutanoic acid (2), containing 0.02 M total monomer (0, 25, 34, 50, 66, 75, 100 mol% 2), 0.05 M sodium dodecyl sulfate, and 0.1 M LiClO4, on gold microelectrodes in an array was investigated. Decreasing monomer deposited (m) from 0 to 100 mol% 2 is attributed to a decreasing pH that inhibits electropolymerization. Molar ratios of …

P450 Cyp17a1 Variant With A Disordered Proton Shuttle Assembly Retains Peroxo-Mediated Lyase Efficiency, Yilin Liu, Ilia G. Denisov, Yelena V. Grinkova, Stephen G. Silgar, James R. Kincaid

Chemistry Faculty Research and Publications

Human cytochrome P450 CYP17A1 first catalyzes hydroxylation at the C17 position of either pregnenolone (PREG) or progesterone (PROG), and a subsequent C₁₇−C₂₀ bond scission to produce dehydroepiandrosterone (DHEA) or androstenedione (AD). In the T306A mutant, replacement of the Threonine 306 alcohol functionality, essential for efficient proton delivery in the hydroxylase reaction, has only a small effect on the lyase activity. In this work, resonance Raman spectroscopy is employed to provide crucial structural insight, confirming that this mutant, with its disordered proton shuttle, fails to generate essential hydroxylase pathway intermediates, accounting for the loss in hydroxylase efficiency. Significantly, …

Eelgrass (Zostera Marina) Population Decline In Morro Bay, Ca: A Meta-Analysis Of Herbicide Application In San Luis Obispo County And Morro Bay Watershed, Tyler King Sinnott

Master's Theses

The endemic eelgrass (Zostera marina) community of Morro Bay Estuary, located on the central coast of California, has experienced an estimated decline of 95% in occupied area (reduction of 344 acres to 20 acres) from 2008 to 2017 for reasons that are not yet definitively clear. One possible driver of degradation that has yet to be investigated is the role of herbicides from agricultural fields in the watershed that feeds into the estuary. Thus, the primary research goal of this project was to better understand temporal and spatial trends of herbicide use within the context of San Luis …

Otolith Age Validation And Microchemical Investigation Of The Northern Stock F Atlantic Black Sea Bass (Centropristis Striata), Elise R. Koob

Graduate Masters Theses

Black sea bass (Centropristis striata) is a demersal marine species that supports extensive commercial and recreational fisheries along the Atlantic coast. A recent expansion into the Gulf of Maine raises questions about this species’ movement and population dynamics in the region. Additionally, the 2016 catch-at-age stock assessment model for the northern stock incorporated a population split at the Hudson Canyon. Though this model better accounts for differences in populations, several issues remain. First, validation of the otolith ageing technique for this stock is incomplete; and, second, the origin of fish that moved into the northern ranges of the Gulf of …

Selective Electrocatalytic Reduction Of Co2 To Co With Iron Nheterocyclic Carbene Complexes And Near-Infrared Absorbance Of Ruthenium(Ii) Photosensitizers Containing A Merocyanine Π-Acceptor, Peter Andrew Catsoulis

Graduate Masters Theses

The catalytic proton-coupled reduction of carbon dioxide into C-1 or “common engine” liquid fuels is currently a highly desirable and green approach to removing anthropogenic CO2 from the atmosphere. The most common approach to this is through electrocatalytic homogeneous reductions utilizing inorganic complexes as catalysts. Current research has moved towards the use of first-row transition metals in catalysts due to their high natural abundances and cheap cost. Iron porphyrin complexes have been vastly studied due to their high product selectivity and turnover frequencies. However, these complexes exhibit short lived activity because of competing reactions in their catalytic cycles, rendering them …

Ph Induced Size Tuning Of Gd2hf2o7:Eu3+ Nanoparticles And Its Effect On Their Uv And X-Ray Excited Luminescence, Santosh K. Gupta, Mitzy A. Penilla Garcia, Jose P. Zuniga, Yuanbing Mao

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

Size tunable nanoparticles (NPs) have played an important role in areas of optoelectronics, drug delivery, magnetism and many others. Moreover, designing size-tunable NPs without exposing them to high temperature and long time thermal treatment is highly desirable to make agglomerate- and defect-free NPs. In this work, we have designed Gd2Hf2O7:Eu3+ (GHOE) NPs using the molten-salt synthesis (MSS) method with the precursors made from varying precipitant concentrations (correspondingly the pH of the precipitating solution). The obtained NPs have a decreasing size as the pH of the precipitating solution rises and a defect fluorite structure with a large fraction of Eu3+ ions …

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse pot …

Predicting The Hydration Free Energy Of Small Alkanes And Alcohols From Custom, Electronic Structure-Based Force Fields, T. Ryan Rogers

Graduate Theses and Dissertations

Mathematical theories reveal the fundamental physics involved in experimentalphenomena. Computer models of such theories are routinely used to corroborate or explain experiments and predict properties of chemical systems. Therefore, an important effort in computational chemistry is the development of more accurate and efficient chemical models. Current-generation models are only beginning to approach experimental-quality predictions of hydration free energies (HFEs).Using computations of quantum mechanical (QM) forces and classical simulations based on these forces, I investigate models to predict several properties of solutes and solutions. This dissertation is a collection of projects exemplifying methods used to gain insight into chemical systems.

Simulations …

Structural Characterization Of Two Large Icosahedral Dna Viruses And Their Capsid Assembly Mechanisms, Yuejiao Xian

Open Access Theses & Dissertations

In the last three decades, many large DNA viruses were discovered and grouped into a loosely defined clade of Nucleocytoplasmic Large DNA Viruses (NCLDVs). NCLDVs infect a wide range of hosts from single cellular protists to large animals. Recently, these viruses were classified as a new phylum of Nucleocytoviricota under the kingdom of Bamfordvirae. The genomes of these Nucleocytoviricota viruses (NCVs) are remarkedly large and complicated, containing many cellular genes from all three domains of life, which raised intensive debates on their evolutionary origins. Despite being classified in the same phylum, their physical structures vary and can be roughly classified …

Fundamental Studies Of Nanomaterial-Mediated Photothermal Effects And Novel Applications In Visual Quantitative Disease Diagnoses, Wan Zhou

Open Access Theses & Dissertations

Infectious diseases and cancers frequently cause public health concerns and high burdens on health care globally. Early diagnosis of these diseases can provide an important guide on prevention, treatment, and prognosis in clinical practice. However, current laboratory diagnostic methods, such as nucleic acid- and protein-based detection methods, require sophisticated infrastructure, expensive and bulky instrumentation, well-trained personnel, and time-consuming processes, which significantly leads to high cost of detection assays and limit their wide accessibility, especially in low-resource settings. To address these issues, we have developed multiple simple, low-cost, and visual quantitative diagnostic methods based on nanomaterial-mediated photothermal effects for the detection …

Dna Aptamer‑Based Rolling Circle Amplification Product As A Novel Immunological Adjuvant, Adil Sabr Al-Ogaili, Rohana Liyanage, Jack O. Lay Jr., Tieshan Jiang, Christine N. Vuong, Shilpi Agrawal, Thallapuranam Krishnaswamy Suresh Kumar, Luc R. Berghman, Billy M. Hargis, Young Min Kwon

Chemistry & Biochemistry Faculty Publications and Presentations

Several agonists to CD40 have shown to induce acquired immune responses. Here, we developed and evaluated the rolling circle amplification (RCA) products that are based on anti-CD40 DNA aptamers as a novel vaccine adjuvant. First, we developed DNA aptamers with specific binding affinity to chicken CD40 extra domain (chCD40ED). Next, we prepared the RCA products that consist of these aptamers to increase the spanning space and overall binding affinity to chCD40ED. Using 8 DNA aptamer candidates, 4 aptamer-based RCA products (aptamer RCAs) were generated, each consisting of two distinct aptamers. We demonstrated that all 4 aptamer RCAs significantly induced the …

Aryne-Guided C-H Functionalization Of Benzenoid Rings Using Diaryliodonium Salts, Aleksandra Nilova

Dissertations and Theses

The benzenoid core is a frequent and irreplaceable component of biologically active molecules. Structure function relationship of these compounds has been broadly analyzed and presented in numerous literature reports. Herein, we augmented existing knowledge by a broad analysis of the benzenoid substitution patterns in small molecule active pharmaceutical ingredients approved by the FDA. Our findings reveal a strong correlation that the most represented substitution patterns are those achieved via S_EAr. Despite the rapid development of methods to functionalize benzenoid rings, the lack of synthetic methodologies to access sterically and electronically unfavorable positions is highlighted. We sought to establish …

Chloramination Of Iopamidol- And Bromide-Spiked Waters Containing Natural Organic Matter, Nana Osei B Ackerson, Hannah K. Liberatore, Susan D. Richardson, Micheal J. Plewa, Thomas A. Ternes, Stephen E. Duirk

Faculty Publications

Iopamidol (an iodinated X-ray contrast medium) and bromide are precursors in the formation of halogenated disinfection byproducts (DBPs). The interactions of these precursors are vital to elucidate the formation of halogenated DBPs during chloramination. This work investigated the formation of total organic halogen and select individual DBPs in two laboratory-chloraminated source waters containing iopamidol and bromide. Experiments were carried out in batch reactors containing Barberton source water (BSW) and Cleveland BSW (CSW), spiked with iopamidol (5 mu M), bromide (15 mu M), and 100 mu M monochloramine. Total organic iodine concentrations were approximately equal regardless of source water since they …

Biosynthetic Gene Clusters, Microbiomes, And Secondary Metabolites In Cold Water Marine Organisms, Nicole Elizabeth Avalon

USF Tampa Graduate Theses and Dissertations

Microorganisms and invertebrate animals from cold water marine environments, such as in Antarctica and in Ireland’s deep sea, are a rich source of secondary metabolites. In this dissertation, research was centered around secondary metabolism and natural product biosynthesis. The projects include the delineation of biosynthetic gene clusters hypothesized to be responsible for the biosynthesis of the palmerolides, stratification of the microbiome of the Antarctic ascidian Synoicum adareanum, genomic and peptidomic analysis of a host-associated Antarctic Pseudovibrio sp., and isolation and characterization of secondary metabolites from the Irish deep-sea coral Drifa sp.

Palmerolide A, the principle secondary metabolite associated with S. …

Unspecified Verticality Of Franck-Condon Transitions, Absorption And Emission Spectra Of Cyanine Dyes, And A Classically Inspired Approximation, Joseph D. Alia, Joseph A. Flack

Chemistry Publications

The computed vertical energy, Ev,a/f, from the equilibrium geometry of the initial electronic state is frequently considered as representative of the experimental excitation/emission energy, Eabs/fl = hc/λmax. Application of the quantum mechanical version of the Franck–Condon principle does not involve precise specification of nuclear positions before, after, or during an electronic transition. Moreover, the duration of an electronic transition is not experimentally accessible in spectra with resolved vibrational structure. It is shown that computed vibronic spectra based on TDDFT methods and application of quantum mechanical FC analysis predict Eabs = hc/λmax …

Multi-Institution Research And Education Collaboration Identifies New Antimicrobial Compounds, Amelia A. Fuller, Amy B. Dounay, Douglas Schirch, Daniel G. Rivera, Karl A. Hansford, Alysha G. Elliott, Johannes Zuegg, Matthew A. Cooper, Mark A. T. Blaskovich, Jacob R. Hitchens, Sarah Burris-Hiday, Kristiana Tenorio, Yanira Mendez, J. Geno Samaritoni, Martin J. O’Donnell, William L. Scott

Chemistry and Biochemistry

New antibiotics are urgently needed to address increasing rates of multidrug resistant infections. Seventy-six diversely functionalized compounds, comprising five structural scaffolds, were synthesized and tested for their ability to inhibit microbial growth. Twenty-six compounds showed activity in the primary phenotypic screen at the Community for Open Antimicrobial Drug Discovery (CO-ADD). Follow-up testing of active molecules confirmed that two unnatural dipeptides inhibit the growth of Cryptococcus neoformans with a minimum inhibitory concentration (MIC) ≤ 8 μg/mL. Syntheses were carried out by undergraduate students at five schools implementing Distributed Drug Discovery (D3) programs. This report showcases that a collaborative research and educational …

Study On Cation Exchange Of A Lead Coordination Polymer Targeting Dynamic Mixed Cation Doped And Mixed-Valent Coordination Polymers, Hamisu Aliyu Mohammed

Student Works (2020-2029)

Solid solution in Metal-Organic Coordination Polymers (MOCPs) is an emerging synthetic pathway for modifying chemical compositions and has been expansively investigated. It has been demonstrated to be an important tool for engineering novel functional materials that otherwise have not been synthesized via the conventional technique. Although stable solid material with variable functionalities and intriguing structural motifs could be engineered by judicious selection of multivariate metal centers and multifunctional ligands. However, solid solution featuring mixed valence in MOCP is rare. Motivated by the ability of Pb2+ to adopt range of coordination numbers (CN) and chemical environments (CE), in addition to its …

Cationic Boron Formazanate Dyes, Benjamin D. Katzman, Paul D. Boyle, Viktor N. Staroverov, Joe Gilroy, Ryan R. Maar

Chemistry Publications

Incorporation of cationic boron atoms into molecular frameworks is an established strategy for creating chemical species with unusual bonding and reactivity but is rarely thought of as a way of enhancing molecular optoelectronic properties. Using boron formazanate dyes as examples, we demonstrate that the wavelengths, intensities, and type of the first electronic transitions in BN heterocycles can be modulated by varying the charge, coordination number, and supporting ligands at the cationic boron atom. UV‐vis absorption spectroscopy measurements and density‐functional (DFT) calculations show that these modulations are caused by changes in the geometry and extent of π‐conjugation of the boron formazanate …

One-Step Synthesis Of Soybean Oil-Based Polyol For Highly Flame-Retardant Rigid Polyurethane Foams, Tenzin Ingsel

Electronic Theses & Dissertations

The usage of petro-chemical based sources in polyurethane has raised environmental concerns in recent years. Bio-based polyurethanes are attractive alternatives for these conventional petrochemical-based polyurethanes. In this work, a soybean oil-based polyol was synthesized via thiol-ene reaction. Chromatography, wet chemistry methods, and spectroscopic evaluations were carried out to characterize the synthesized polyol. The polyol obtained was then used to produce flame-retardant rigid polyurethane foams with three different organophosphorus flame-retardants: dimethyl methyl phosphonate (DMMP), triethyl phosphate (TEP), and triphenyl phosphate (TPP). Incorporating flame-retardants in polyurethane foams provide them resistance to ignition where these foams are originally highly combustible. Physico-mechanical and flammability …