Chemistry Commons^™

An Integrated Pcb-Based Heating And Auto-Ranging Platform For Volatile Organic Compound (Voc) Detection Using Carbon Nanotube Based Sensors, Thomas Kalach

USF Tampa Graduate Theses and Dissertations

This thesis presents the development, characterization, and integration of a novel low-cost, high-dynamic-range sensor platform for the detection of volatile organic compounds (VOCs), leveraging the unique electrical properties of carbon nanotube (CNT) thin films. The platform introduces a fully integrated auto-ranging analog front-end circuit capable of real-time resistance measurement spanning over eight orders of magnitude ranging from tens of ohms to hundreds of megaohms, without compromising signal resolution or precision. This was achieved through a digitally controlled, multi-path feedback architecture and controllable current source.

To further enhance sensor performance, the system incorporates a copper trace heater beneath the sensor array, …

Introductory Chemistry Student Success: Investigating Study Strategies And Evaluating An Informative Utility Value Intervention, Pallavi Nayyar

USF Tampa Graduate Theses and Dissertations

Improving retention in STEM (science, technology, engineering, and mathematics) programs is essential to meet the growing demand for skilled professionals in the domestic workforce. To achieve this, it is critical to understand and address the factors that influence student persistence in STEM degrees. Gateway courses such as general chemistry often serve as early barriers to STEM degree completion, with high rates of attrition that impact not only individual students but also institutions and society. Therefore, the aim of this work was to examine and influence the factors that contribute to student withdrawal from introductory chemistry courses in order to promote …

Investigating Factors Influencing Organic Chemistry Learners' Explanation Sophistication And Representational Competence, Caroline J. Crowder

USF Tampa Graduate Theses and Dissertations

The research presented in this dissertation has two themes: organic chemistry learners’ written explanations and representational competence. Chapters 3 and 4 explore how organic chemistry learners construct explanations of reaction mechanisms, specifically focusing on electrophile and nucleophile components. Chapter 5 investigates organic chemistry learners’ representational competence skills and the relationship between these skills and their performance in the course.

Understanding reaction mechanisms is critical for success in organic chemistry, yet learners often struggle to reason beyond explicit, surface-level features. Constructed-response prompts that ask learners to explain what is happening in a reaction mechanism and why it occurs can provide insight …

The Synthesis Of A Photo-Affinity Probe Library For The Fatty Acid Amide Proteome And The Endocannabinoid System Within, Robert E. Feeney Iii

USF Tampa Graduate Theses and Dissertations

Fatty acid amides are a large family of endogenous metabolites with significant biological activity, including that of the endocannabinoid system. Currently little is known about how this system of tightly regulated compounds works within humans. This work lays the foundation to explore the structure-activity relationship driving the selectivity of ligand-protein interactions involved with fatty acid amides. A library of activity-based proteomic profiling probes for fatty acid amides has been synthesized to this end. Additionally, progress towards phytocannabinoid probes has been made as well.

Development And Photophysical Characterization Of Bioinspired Materials, Qaisar Maqbool

USF Tampa Graduate Theses and Dissertations

Porphyrins are versatile aromatic macrocycles with unique photophysical properties that make them attractive for applications in light harvesting, photocatalysis, and sustainable energy conversion. Incorporating porphyrins into metal-organic frameworks (MOFs) offers a unique opportunity to modulate their photophysical behavior through spatial confinement and host–guest interactions. This thesis explores how structural modifications influence porphyrin excited-state behavior through a multi-stage investigation. The work begins by comparing the photophysical properties of two cationic porphyrins: tetra(N-methylpyridyl) porphyrin(TMPyP) and tetra(4-N,N,N-trimethylanilinium) porphyrin(4TANP). While TMPyP exhibits significant singlet–charge transfer (S₁–CT) state mixing due to charge delocalization onto peripheral pyridinium groups, 4TANP lacks comparable behavior. The localized nature of …

Development Of S(Vi) And S(Iv) Chemistry: From Asymmetric Synthesis To Covalent Reactive Groups, Chuan Shan

USF Tampa Graduate Theses and Dissertations

This dissertation mainly covers the development of synthetic methodologies related to several heteroatom functional groups, including phosphonates P(V), sulfoximines S(VI), sulfonimidamides S(VI), sulfonimidoyl fluorides S(VI), and sulfinamides S(IV). The interests in these functionalities are not only out of chemistry curiosity but also due to their pharmaceutical importance indicated by the existing drug molecules that contain these functional groups. The first chapter introduced the importance of phosphonates in biochemistry and organic synthesis, also provided some essential background of our synthetic efforts. The second chapter described the phosphonate synthesis from commercially available starting materials, with the purpose to obtain heterocyclic phosphonates in …

Efforts To Improve General Chemistry Student Success: Describing Stoichiometry Solution Patterns And Investigating Challenge Perceptions, Dianna Kim

USF Tampa Graduate Theses and Dissertations

There is a need for capable STEM graduates to fill needed STEM career gaps, particularly for people who have been historically under-represented in the STEM field (e.g., women, people of color, people of lower economic status, etc.). A course that have great impact would be General Chemistry which typically acts as a pre-requisite for manty STEM majors and careers. The efforts to be described in this thesis was conducted at a large, public doctoral granting university in the southeastern United States of America. The first effort described in this thesis explores how students solve different types of stoichiometry-based problems along …

Development Of Peptidomimetics Based On Γ-Aapeptide Molecular Scaffolds To Modulate Amyloid Peptide Aggregation, Heng Liu

USF Tampa Graduate Theses and Dissertations

Many proteins contain fragments that become structured upon binding to specific targets or through self-association. Notable examples of such disorder-to-order transitions include amyloidogenic proteins like amyloid-β peptide (Aβ) and tau peptide in Alzheimer's disease, α-Synuclein in Parkinson's disease, and hIAPP in type 2 diabetes, and so on. These regions can aggregate into amyloid fibrils through β -sheet stacking, contributing to amyloidosis and related diseases. Although direct link between amyloid formation and neurodegenerative disease development is not fully understood, developing effective inhibitors of these amyloid peptides remains promising both for fundamental research and therapeutical advance.

We have developed a new class …

Regioselective Hydroamination Of Unactivated Olefins With Diazirine And Total Synthesis Of Nostodione A And Scytonemin, Qingyu Xing

USF Tampa Graduate Theses and Dissertations

As an atom-economic way of carbon-nitrogen bond formation, hydroaminations are great tool for make amines, hydrazines, and other nitrogen-containing heterocycles. Specifically, radical hydroamination is a useful approach for functionalization of unactivated olefins, especially in sterically hindered environments. Diversification remains a challenge for radical hydroaminated products, since the nitrogen sources are carefully designed. In the first chapter of this dissertation, we report a highly diversifiable radical hydroamination reaction with diazirine as a nitrogen source and its potential applications in synthesis of several pharmaceutical interested compounds. Cobalt catalyzed regioselective hydroamination with diazirine shows wide function group tolerance, like phenyl thioether, ketones, esters, …

The Discovery Of First Ret Protac With In Vivo Activity, Yafeng Wang

USF Tampa Graduate Theses and Dissertations

This report mainly discusses the development of RET Proteolysis targeting chimera PROTAC molecules based on Selpercatinib (LOXO-292) and Sulfono-γ-AApeptide PROTAC. A PROTAC molecule is a bifunctional molecule composed of two active domains and a linker. It works by inducing selective protein intracellular degradation. This technology was first discussed by Kathleen Sakamoto, Ray Deshaies and Craig Crews in 2001. Using various E3 Ligase, such as CRBN, pVHL, beta-TrCP1, Mdm2, DCAF15, DCAF16, RNF114, and c-IAP1, the PROTAC technology has been applied to several novel drug development,. Yale University licensed the PROTAC technology to Arvinas in 2013–14. For my research, Chapter one summarizes …

The Asymmetric Total Synthesis Of Membranolide And Efforts Towards The Oxeatamides, Sean Bradley

USF Tampa Graduate Theses and Dissertations

Total synthesis is a discipline within organic chemistry that is a constant force that propels the field forward. In our lab, we have immersed ourselves within the field of total synthesis to gain access to complex natural products, perform SAR studies, as well as highlight interesting methodology. Within these endeavors, we have completed the first asymmetric synthesis of membranolide. This has allowed us to explore potential biofilm eradication in our efforts to develop novel therapeutics to combat the ESKAPE pathogens and multi-drug resistance. We have also begun to pursue the first asymmetric total synthesis of the oxeatamides. By utilizing our …

Predicting Ph At In-Situ Temperature For Aquatic Environments, Sarah E. Bartoloni

USF Tampa Graduate Theses and Dissertations

pH is typically measured at a constant temperature and, as needed, converted to in-situ temperature using a system of thermodynamic equations. Using this equilibrium approach, adjustment of pH to in situ conditions requires two measured CO2 system parameters (pH, total alkalinity, dissolved inorganic carbon, or CO2 fugacity). Currently, when pH is the only measured CO2 system parameter, linear models are used to adjust the pH to in-situ temperature. Although many studies have attempted to optimize CO2 equilibrium constants (K1 and K2) for the CO2 system over a range of conditions, very little prior work has experimentally examined which CO2 system …

A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky

International Journal of Speleology

Speleogenesis in hypogene karst settings may be closely tied to regional tectonic dynamics and concomitant hydrochemical evolution of karst waters. However, placing temporal constraints on these processes can require a wider array of field observations and techniques than for typical karst systems. Herein, we present a comprehensive study of Novoafonskaya Cave (Western Caucasus, Abkhazia). The updated speleogenetic history of the cave comprises four stages: (1) the most ancient, a low-T hydrothermal (ca. 40–50°C) priming stage; (2) the main stage enabled by mixing of upwelling thermomineral and locally recharged common karst waters; (3) the late sulfuric-acid speleogenesis (SAS) stage, which left …

Introductory Chemistry Student Success: Evaluating Peer-Led Team Learning And Describing Sense Of Belonging, Jessica D. Young

USF Tampa Graduate Theses and Dissertations

Identifying approaches that make science and engineering education broader and more inclusive is core to discipline based education research. Both fundamental and applied research are important in advancing a STEM education that retains the necessary scientists of the U.S.’s future. Thus, the major goal of this work was to evaluate and describe efforts that promote student success within introductory STEM courses. This began with applied research by utilizing quantitative analyses like case-matching, logistic regression, independent sample t-tests, and repeated measures while evaluating the efficacy of peer-led team learning (PLTL). Later, this work delves into qualitative approaches to answer fundamental research …

Explorations On Non-Covalent Interactions: From Supramolecules To Drug-Like Molecules, Zhanpeng Zhang

USF Tampa Graduate Theses and Dissertations

Non-covalent interactions are everywhere in our material world. From the microstructures of organisms to the functional materials used in industrial production, whenever matter exists, there are non-covalent interactions between the molecules that build up the matter.The exploration of non-covalent forces helps people understand the intrinsic principles of life processes, it can be applied to create new supramolecular materials as well. Supramolecular chemistry is a research field focusing on the properties and applications of non-covalent interactions. Various non-covalent interactions, such as hydrogen bonds, metal-ligand coordination, π-π interaction, hydrophobic interaction, etc., are objects of research in supramolecular chemistry.

Not only supramolecular chemists, …

Surface Modification Of Poly(4,4'-Oxydiphenilene Pyromellitimide) With Low-Pressure Plasma Treatment, Cihan Aktas

USF Tampa Graduate Theses and Dissertations

This study explores the change of the wetting characteristics of commercially availablepolyimide (PI), Kapton® HN, films a type of poly(4,4′-oxydiphenylene-pyromellitimide), following treatment with low-pressure plasmas of carbon tetrafluoride (CF4), air, hydrogen (H2), carbon-dioxide (CO2) and oxygen (O2) gases as well as the surface texturing via laser-exposure procedure. The water contact angle (CA) and surface free energy (SFE) of untreated PI films were determined as 82.4°±0.8 and 45.0±0.3 mN/m, respectively. After CF4 plasma gas treatment, the CA value of PI films increased to 110.2°±1.0, while it decreased to 9.3°±2.3 after O2 plasma gas treatment. The surface free energy (SFE) of PI …

Methods For Analytical And Biophysical Analysis For Investigation Of Stimulator Of Interferon Genes In Drug Discovery, William Emmett Brian Lawless

USF Tampa Graduate Theses and Dissertations

This work elaborates on analytical and biophysical techniques including high pressure liquid chromatography (HPLC), mass spectrometry quadrupole time-of-flight (MS-QToF), dynamic light scattering (DLS), microscale thermophoresis (MST), surface plasmon resonance (SPR), isothermal calorimetry (ITC), size exclusion chromatography, and native gel electrophoresis. A basic overview is described for each technique and is designed for easy understanding by both novice and experienced analysts. Best practices for each technique are discussed and suggestions are made for protocol improvements or troubleshooting. Protocol development is discussed, and a method is introduced for MST that can be adapted to any target protein for rapid screening of analog …

In Silico And In Vitro Drug Discovery Strategies And The Chemical Investigation Of Endophytic Fungi, Sarah Grace Dietrick

USF Tampa Graduate Theses and Dissertations

The biodiversity of our global marine ecosystems provides substantial treasure to discover: chemistry. Marine organisms that live in proximity to one another use their unique chemistry to compete with one another and thrive in their environment. Benthic invertebrates, specifically, that lack physical means of protection will produce secondary metabolites as a means of defense from their surroundings and predators. The compounds which they produce are ordinarily species-specific, highly diverse biomolecules. Biosynthetic processes within an organism construct these secondary metabolites from fragments of primary metabolites (amino acids, fatty acids, sugars, and so on). Their roles in protection have antibiotic, toxic, and …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Synthetic Studies Of Potential New Ketogenic Molecules, Mohammad Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The ketogenic diet has gained popularity in the past few decades among people and physicians due to its various health benefits. A significant amount of research has been done for the modification of the original ketogenic diet and investigation of its potential health benefits. However, synthesis of novel ketogenic compounds as a dietary supplement has not received the same level of attention. That is the primary objective of this research project. The first chapter of this manuscript describes the synthesis of various short and medium chain esters of different polyols that have been done so far, and areas of their …

Utilizing Binding-Based Proteomic Profiling And Mass Spectrometry Imaging As Innovative Tools For Lipid Research, Suzeeta Bhandari

USF Tampa Graduate Theses and Dissertations

Mass spectrometry-based omics research involves global identification and quantification of molecules in the biological system, which can form the basis of the multi-omics approach integrating multiple layers of information to provide a comprehensive overview of systems biology. The investigation of fatty acid amides (FAA) is one such research avenue that benefits significantly from the high-throughput, multi-level, and interdisciplinary approach of integrative omics. Currently, FAA research is dominated by lipidomic-based studies that have successfully identified and quantified >100 different FAAs in different model systems. Few studies are credited with exploring the biological function and evolution of FAA-dependent signaling pathways. Previous literature …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Discovery Of Small-Molecule Inhibitors For The Β-Catenin/B-Cell Lymphoma 9 Protein-Protein Interaction., Zilu Li

USF Tampa Graduate Theses and Dissertations

The Wnt/β-catenin signaling pathway is associated with activating genes that support cell proliferation, differentiation, and survival. Excessive activation of Wnt/β‐catenin signaling has been associated with development of several types of cancer and activation of stem-like cancer cells. Direct targeting of β‐catenin, the central hub in this signaling pathway, is a promising strategy to suppress the hyperactive β‐catenin signaling but has proven to be highlychallenging. Substantial efforts have been made to discover compounds that bind with β‐catenin, block β‐catenin mediated protein–protein interactions (PPIs) and suppress β‐catenin signaling. β‐catenin/BCL9 PPI has a smaller contacting area (1450 Å2) and a moderate binding affinity …

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

Development Of Bioactive Peptidomimetics, Lei Wang

USF Tampa Graduate Theses and Dissertations

In the past two decades, a lot of different peptidomimetics, such as β-peptides, oligoureas, azapeptides, peptoids, aromatic oligoamides, and others, have been developed. These peptidomimetics with distinctive scaffolds have shown potential in protein surface recognition and mimicry, PPI regulation, catalysis, etc. Moreover, these bioactive peptidomimetics demonstrate much better bioavailability and biostability than the bioactive peptides. To expand the application of peptidomimetics, our group have developed a new sequence-specific peptidomimetics- γ-AApeptide, which is derived from chiral γ-PNA. It shows excellent advantages including highly resistant to various proteolytical degradations and has the potential to increase chemodiversity. γ-AApeptide also exhibits remarkable biomedical applications, …

Development Of Antiviral Peptidomimetics, Songyi Xue

USF Tampa Graduate Theses and Dissertations

Protein-protein interactions (PPIs) are essential for biological processes and are associated with a number of diseases, including cancer, infectious diseases, and neurodegenerative diseases. As a result, modulation of PPIs has been recognized as one of the most promising strategies to develop the novel drugs. Peptide modulators always exhibit higher specificity and affinities with targets than small compounds or monoclonal antibodies, but their broad medicinal effectiveness is constrained by their poor bioavailability and biostability. Peptidomimetics, which have been developed to mimic the structure as well as function of bioactive peptides and proteins, have shown excellent potential in protein surface mimicry and …

Synthesis Of Tools For The Investigation And Treatment Of Infectious Diseases, Grant Lawrence

USF Tampa Graduate Theses and Dissertations

Modern medicine’s ability to treat a wide array of diseases is due mainly to the development of small-molecule drug discovery. Thousands of years of traditional medicines have been dwarfed in less than a hundred years. In addition, drug discovery has becoming a more consistent process with the introduction of the clinical trials process as well.Plasmodium is a genus of tropical parasites that have the potential to wreak havoc on billions of people globally. Current methods of drug discovery aimed at defeating these parasites require expensive assays that use radioactive material. By using an alkyne-labeled agent instead of a tritium-labeled agent, …

Synthesis Of Small Molecule Modulators Of Non-Traditional Drug Targets, Jamie Nunziata

USF Tampa Graduate Theses and Dissertations

This work details the effort toward structure-activity-relationship (SAR) studies and synthesis of the small molecule modulators of two non-traditional drug targets. The first part of this manuscript (chapters 1–2) will discuss the collaborative work and synthesis of an inhibitor of Slingshot Homology 1 (SSH1) with the potential therapeutic application toward Alzheimer’s Disease (AD) treatment. The second part (chapters 3–6) will discuss the synthetic efforts toward modulation of a protein target known as STING, or stimulator of interferon genes, with the therapeutic application toward autoimmune disease or anti-tumor activity.

AD is a progressive and degenerative illness that holds the title of …