Chemistry Commons^™

Investigating The Applications Of Peps To The Measurement Of The Stabilities Of Staphylococcal Nuclease (Stw) And Human Acidic Fibroblast Growth Factor (Hfgf1), Motolani Omolade Matthew

Graduate Theses and Dissertations

This dissertation presents a detailed investigation into the applications of Protein Equilibrium Population Snapshot H/D Exchange Electrospray Ionization Mass Spectrometry (PEPS-H/D exchange or PEPS) method. This method is based on protein equilibrium unfolding, and its fundamental capability is to capture a "snapshot" of the protein's state, allowing us to monitor the ratio of the unfolded to folded populations at different chemical denaturant concentrations. First, to increase the accuracy of PEPS data analysis for assessing protein stability, the traditional linear extrapolation method (LEM) was replaced. Instead of using LEM, which calculates free energy change based on the peak ratio of unfolded …

Quantum Modeling & Experimental Studies Of Radical Chemistry, Justin Michael Barrett

Graduate Theses and Dissertations

This work describes two projects centered around radical chemical mechanisms. The first investigation generalized the utility of a C-N bond homolysis followed by a [1,3] – rearrangement synthetic strategy found possible in N-alkylated thiazole & benzothiazole species onto analogous systems. Computational investigation guided the inquiry on structurally analogous systems that would favor a radical, [1,3] – rearrangement. Herein, we describe the implementation of that mechanism to transform Breslow Intermediate-like substrates into tertiary alcohol and amide products under facile conditions. We confer on the proficiency of this strategy with 2-pyridinemethanol and the problematic implementation with 2-(aminomethyl)pyridine. The second investigation solved a …

Application Of Functionalized Organosilicas In Adsorption Of Nitrates, Stephen Amoako

Electronic Theses and Dissertations

This study addresses the critical environmental issue of elevated nitrate levels in water bodies, primarily due to excessive use of nitrogenous fertilizers and improper waste disposal. It focuses on reducing nitrate concentrations in polluted water to permissible levels through the effectiveness of hybrid materials in nitrate adsorption. We synthesized nine amino-functionalized adsorbents using grafting and sol-gel techniques. Batch adsorption tests confirmed the high nitrate adsorption capacities of these adsorbents, with sol-gel materials showing the highest efficiency due to their abundant amino group contents. Among these, the surfactant-free, sol-gel adsorbent was the most effective, combining ease of synthesis with cost-efficiency. Our …

We Think, We Smell, We Remember: The Effect Of Smell On Memory For Chemistry Lab Learning, Michael A. Marino, Francine Wisnewski, Catherine Reilly, Andre Alexis

BCES: Faculty Presentations

The traditional five senses are the primary receptors of external stimuli for the brain. While tactile learning and visual observations are integral to the chemistry laboratory, olfaction is a sense that should be considered part of an educator's repertoire. Previous studies have discovered that our sense of smell plays a significant role in triggering memories. Moreover, specific scents like vanillin can prompt anamneses to recall previous experiences. A sample of 61 college students was employed for a three-week pretest-posttest control group experimental design. In the first week, participants conducted a chemical reaction to synthesize isoamyl acetate, the familiar and nontoxic …

Synthesis Of Portions Of An Acinetobacter Baumannii Lipooligosaccharide (Los), Brandon Conrad

LSU Doctoral Dissertations

Glycoconjugate vaccines have become an effective strategy for protection against an array of globally persistent diseases resulting from pathogenic bacteria such as Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Salmonella enterica serotype Typhi. Comprised of a carbohydrate (referred to as glycan) covalently inked to a carrier protein, these vaccines can initiate adaptive immunity by inducing B and T cell responses once in the lymphatic system. This is particularly relevant for infants two years of age and younger whose immune systems are not fully developed. A continuously emerging threat in clinical settings, Acinetobacter baumannii is a Gram-negative bacterium …

Novel Approaches To The Activation Of Chalcogenoglycosides For O-Glycosylation, Tiffany Duong

LSU Doctoral Dissertations

Carbohydrates are integral to various biological processes such as cell signaling, function and regulation. Carbohydrates also play critical roles in various disease and metastatic pathways. This has garnered considerable attention to the field of glycoscience, however, the study of carbohydrate-containing compounds remains a challenge due to the difficulty in obtaining pure samples from natural sources. As a result, the biological evaluation of carbohydrates relies on synthetic chemistry to produce pure compounds in significant quantities. However, the synthesis of carbohydrates present their own challenges owing to the complexity in controlling stereochemistry and regiochemistry. The most significant of these challenges is controlling …

Advances In Stereoselective Glycosylation: Electron-Withdrawing Groups, Benzyne-Mediated Stereoinversion, And Visible-Light Photochemistry For 1,2-Cis O-Glycosylation, Erik Giovanni Alvarez Valenzuela

LSU Doctoral Dissertations

The symbiotic relationship between humans and their microbiota is essential for health, with imbalances in the complex microbiota ecosystem linked to a variety of disorders ranging from neurodegenerative to gastrointestinal diseases. Bacteria within the human microbiota, comprising over 1000 known species, are densely and diversely coated with oligosaccharides crucial for functions like cell recognition, communication, signaling, adhesion, proliferation, and pathogenic inhibition. However, studying the structure-activity relationships of these sugars which are also secreted by bacteria is challenging due to difficulties in obtaining homogenous samples from natural sources.

Chemical synthesis offers a solution by enabling the production of well-defined oligosaccharides in …

Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe

Markey Cancer Center Faculty Publications

Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and re- combination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.

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 …

Nanoparticles As Antioxidant Agents: A Comprehensive Review, Sulyman Olalekan Ibrahim, Halimat Yusuf Lukman, Fatimat Ronke Abdulkadir, Monsurat Yemisi Bello, Yusuf Oloruntoyin Ayipo, Halimah Funmilayo Babamale, Marili Funmilayo Zubair, Olubunmi Atolani

Al-Bahir

This study seeks to provide a comprehensive overview of the latest progress in the antioxidant properties of nanoparticles. Nanoparticles (NPs) have emerged as a promising tool in several domains of science and industry, including their application as antioxidant agents. The main knowledge gaps seem to be in correctly identifying the make-up of the naturally occurring phytochemicals that give these nano-antioxidants their extraordinary pharmacology and drug-like properties. In many instances, that characterization is done using spectroscopy instrumentation such as fourier-transform Infrared (FT-IR), scanning electron microscope (SEM), and X-ray diffraction analysis (XRD). From literature appraisals, it was discovered that a lot of …

Development Of Platinum(Iv)-Gold(I)-Based Anticancer Agents, Javier E. Lopez-Hernandez

Dissertations, Theses, and Capstone Projects

Heterometallic compounds have emerged as prospective multitarget anticancer drugs. These species may display improved efficacy and physicochemical properties compared to the individual metallic fragments, while helping combat drug resistance by exerting effects on multiple pathways. In this thesis we describe the synthesis of new bi- and tri-metallic compounds based on platinum(IV) compounds containing FDA-approved platinum agents, and gold(I) derivatives with known anticancer properties. We demonstrate their toxicity and selectivity against a small panel of renal, bladder, ovarian, and breast cancer cell lines, as well as their synergistic effects. We have selected a trinuclear PtAu₂compound containing the Pt(IV) core …

Mechanistic, Biochemical, And Theoretical Studies Of Phototoxicity And Photobluing, Lloyd M. Lapoot

Dissertations, Theses, and Capstone Projects

This thesis consists of four chapters as detailed below:

Chapter 1 discusses the photoconversion of heptamethine to pentamethine cyanines and of pentamethine to trimethine cyanines. Here, we report mechanistic studies and initial experimental evidence for a previously unexplored 4-carbon truncation reaction that converts the simplest heptamethine cyanine to the corresponding trimethine cyanine. We propose a DFT-supported model describing a singlet oxygen (¹O₂) mediated formation of an allene hydroperoxide intermediate and subsequent 4-carbon loss through a retro-Diels-Alder process. Fluorescence and mass spectrometry measurements provide evidence for this direct conversion process. This 4-carbon truncation reaction adds to growing …

Anion Binding And Sensing Using Cs124-Sensitized Luminescent Terbium Complexes, Alessandro Rizzi, Minhee Lee, Wade Grabow, Olivia Brooks, Helena Nguyen, Neal Yakelis, Clarisse Vanderfeltz

Honors Projects

Two terbium complexes with varying degrees of intramolecular coordination, Tb:DO2A-Cs124 and Tb:DOTA-Cs124, were prepared. Their capacity to detect biologically and environmentally relevant anions through their luminescence changes was investigated. Tb:DOTA-Cs124 demonstrated exceptional selectivity as a sensor for nitrite, while Tb:DO2A-Cs124 detects nitrite, phosphates, and a range of carboxylate-containing anions.

Visible-Light Photocatalytic C-H Amination Of Arenes Utilizing Acridine-Lewis Acid Complexes, Matthew R. Lasky, En Chih Liu, Matthew S. Remy, Melanie S. Sanford

Chemistry Faculty Research & Creative Works

This report describes the development of a visible-light photocatalytic system for C(sp²)-H amination that leverages in situ-generated photocatalysts. We demonstrate that the combination of acridine derivatives and Lewis acids form potent photooxidants that promote the C-H amination of electronically diverse arenes upon irradiation with visible-light (440 nm). A first-generation photocatalyst composed of Sc (OTf)₃ and acridine effects the C-H amination of substrates with oxidation potentials ≤ +2.5 V vs SCE with pyrazole, triazole, and pyridine nucleophiles. Furthermore, the simplicity and modularity of this system enable variation of both Lewis acid and acridine to tune reactivity. This enabled …

Efficient And Chemoselective Access To Highly Functionalized Arenes By C-H Deprotonative Generation Of Aryne Intermediates, Bryan Edward Metze

Dissertations and Theses

Arenes are a ubiquitous structural motif occurring in numerous organic pharmaceuticals, agrochemicals, secondary metabolites, and functional materials. As such, studies on the characterization, functionalization, and properties of arenes have been a central pillar of organic chemistry since its inception. Early methods to synthesize complex benzenoid rings focused on ring functionalization rather than ring construction due to the high accessibility of very simple arenes and the wide range of aromatic substitution reactions discovered in the late 19th century. As the importance of arenes was recognized more methods of building complex arenes emerged. Both classical and modern approaches are still somewhat limited, …

The Lewis Acidity Of Imidazole-Derived Diaryliodonium Zwitterions, Cyrus Rose

University Honors Theses

Diaryliodonium salts can be used as effective aryl-transfer agents in reactions to form novel molecules with diverse applications including pharmaceuticals and agrochemicals without using harsh reaction conditions and transition metal reagents. In recent years, interest in the applications of the Lewis acidity of iodonium ion catalysts has increased. Despite this, the quantification of the Lewis acidities of diaryliodonium salts are scarce. Even rarer, there has not been much study into the Lewis acidities of zwitterionic diaryliodonium salts. For zwitterions, there is no counter anion that would come into consideration in regard to its Lewis acidity. To expand the understanding of …

Cleaner, Green Oxidation Chemistry: Development Of New Oxoammonium- And Nitroxide- Mediated Transformations, Katrina Doherty

Honors Scholar Theses

This work investigates various key oxidation and oxidative functionalization reactions that occur using a bench-stable nitroxide and its oxoammonium nitrate salt congener. Such transformations include amidation of aldehydes to acyl azoles or hexafluoroisopropyl esters and oxidation of alcohols to ketones or aldehydes. These transformations are key, everyday reactions within organic chemistry, and the aim to make them cleaner and greener is essential to the future of chemistry. Novel compounds produced by these green methods will also be discussed, as well as the results of a scale-up protocol showing the efficacy of the reactions on a process chemistry level. As an …

Examining The Authenticity Of The 'Ether Model' In Certain O-Glycosylation Reactions, Varad Vinayak Agarkar

LSU Doctoral Dissertations

Acinetobacter baumannii is a gram-negative bacterium species that is responsible for nosocomial infections. It has shown antibiotic resistance and has been designated an urgent threat by the CDC. In Chapter 1, I highlight my efforts in the synthesis of a Kdo building block in the journey towards the construction of an A. baumannii lipooligosaccharide (LOS) core pentasaccharide- a potential candidate for glycoconjugate vaccine against A. baumannii infection. I talk about various optimizations and improvements in the Kdo monosaccharide synthesis and the mechanistic insights I provided about a critical transformation in the synthetic sequence.

Chemical O-glycosylation is a significant research …

Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah

Theses and Dissertations

The industrial revolution came with its downside of emission of greenhouse gases into the atmosphere. The NOAA reported in 2019 that, of the greenhouse gases emitted into the atmosphere, CO2 contributed to about 80% of the increased greenhouse gases hence the need for CO2 Sequestering and Storage (CSS) and ultimately leading to Carbon Capture and Recycling (CCR) as a viable option to convert CO2 into useful forms. The race to find the best catalyst for CCR has led to the synthesis of many organometallic compounds. Pincer complexes catalyzed CO2 reduction has gained notoriety recently because of the tunability and robustness …

Synthesis And Analysis Of A Novel Magnetic Surfactant, Donovan Turpin

Honors Theses

Researchers in the University of Mississippi Chemical Engineering Department have suggested that chelation of a large magnetic transition metal, namely dysprosium, into the large polar head group of a surfactant could result in a magnetic surfactant. This project was aimed at synthesizing a surfactant with a large enough head group and negative charge (specifically EDTA) to support this ion and demonstrating that the chelation process was successful. If so, the molecule would ideally be capable of forming micelles which could extract oily substances from water using a strong magnet—possibly applicable to environmental crises like oil spills.

NMR analysis has suggested, …

Purification And Isolation Of Α-Chloro-Β-Lactone Precursor Molecules, Matthew Ellis

Honors Projects

This research investigates the synthesis of α-chloro-β-lactone molecules, focusing on the production, isolation, and purification of two precursor compounds from chloroacetic acid and substituted benzaldehydes. While multiple methods were explored, including EDC, DIC, and DCC catalysis, DCC proved to be most effective in producing higher yields. However, challenges in purification arose due to the formation of byproducts, particularly with DCC, prompting further investigation for efficient extraction and purification techniques. DCC, however, shows a promising route for α-chloro-β-lactone synthesis, despite purification complexities.

Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao

Graduate Theses and Dissertations (2019 - present)

Biochar, a naturally occurring and renewable carbon material, becomes porous through activation. Activated biochar is an ideal candidate for use as an adsorbent. The objective of this study is to investigate whether activated biochar derived from Colorado soft pine serves as a better adsorbent and demonstrates enhanced adsorption capabilities after undergoing secondary physical activation at various activation times. The effect of secondary action time on physical adsorption properties drawn from the analysis of isotherm plots, surface areas and pore size patterns were examined by using a physisorption analyzer. Chemical structures were identified using both ultimate and proximate analyses, while porosity …

The Effects Of Free Volume And Processing On The Development Of Gas Separation Membranes, Jacob Schekman

Dissertations

Structure, thermal, mechanical, gas transport, and free volume properties of thiol-ene based systems are investigated and discussed. In the pursuit of generating low energy-cost polymer membranes for gas separation, it became apparent that UV-curing of thiol-ene materials presented several routes toward achieving this goal. Network structure plays a vital role in determining the gas transport properties of membrane materials. UV photopolymerization techniques provide a means to rapidly vitrify network morphologies which can be tuned depending on choice of monomer. Thiol-ene monomers offer a broad range of precursor materials from which to choose for the design of functional membrane materials.

Chapter …

Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu

Theses and Dissertations

The chiral hydrazine is a crucial structural motif that serves as pivotal structural elements in numerous natural products and biologically significant molecules. We are particularly interested in the catalytic asymmetric reduction of hydrazones, as well as the catalytic asymmetric propargylation and allenylation of hydrazones, because they provide direct pathways to these enantio-enriched chiral building blocks. In this work, we will explore the potential of two different categories of chiral Lewis base catalysts in the said transformations.

Developed by another student in our group, axial-chiral 3,3’-triazolyl biisoquinoline N,N’-dioxides derived catalysts are tested and demonstrated its capability in activating various hydrazone …

Investigations Into The Expansion Of Breslow-Type Intermediate Reactivity Via Radical C-N Bond Homolysis, Jacklyn J. Kubik

Graduate Theses and Dissertations

The Breslow intermediate is a key intermediate in catalytic transformations like the benzoin condensation and Stetter reaction. These intermediates were first postulated by Ronald Breslow in 1958. Since then, a number of researchers have sought to prove their existence and expand upon the reactions possible using these intermediates. In the sixty plus years since this intermediate was first postulated the reaction scope has expanded significantly, Breslow and breslow-type intermediates have expanded to encompass benzothiazoles, imidazoles, benzoimidazoles, triazoles, thiadiazoles, diamino type structures, and most recently pyridine structures. The expansion of these reactions has opened up new avenues of exploration and previously …

A Conceptual Understanding Of Concepts In Organic Chemistry, Timerra Chisham

Theses/Capstones/Creative Projects

As students continue to make the transfer into organic chemistry from general chemistry, they will have to adjust to the new type of thinking required so that they will not fall behind in understanding material and will have success in the course. For this research project, I explored which concepts taught in organic chemistry are the most difficult for students to grasp. I had two main goals for this project. The first one is the central idea that I focused on, which was to see which concepts that have been taught in Organic Chemistry 1 the students are most confident …

Synthesis And Structure Of Curaxin Analogs, Elizabeth E. Brown

Forensic Science Master's Projects

Curaxins are small molecules that have demonstrated anti-cancer activity through the activation of p53 and inhibition of nuclear factor-kB. Curaxins interfere with DNA-histone interactions, impeding DNA repair and inducing chromatin destabilization. This leads to apoptosis through alterations in spatial genome organization and oncogene expression. The results are due to DNA binding activity. A team of researchers, including a Roswell Park Cancer Institute group, discovered these molecules. This project aims to synthesize a diverse library of novel analogs of curaxin through a modified literature protocol to enhance the chemotherapeutic potency while minimizing non-specific cytotoxicity. N-alkylation of diacetyl carbazole followed by saponification …

Design, Synthesis, And Optimization Of Allosteric Inhibitors Of Hiv-1 Integrase, Krunal H. Patel

Dissertations

The human immunodeficiency virus type 1 (HIV-1) infection remains a global health crisis, necessitating the development of innovative antiviral strategies. During the integration step, HIV-1 integrase (IN) interacts with viral DNA and the cellular cofactor LEDGF/p75 to effectively integrate the reverse transcript into the host chromatin. Recently, a novel class of antiretroviral agents called Allosteric Inhibitors of HIV-1 Integrase (ALLINI) compounds has emerged as a promising avenue in the fight against HIV-1. While originally designed to inhibit IN-LEDGF/p75 interactions, these compounds have been shown to also impact late-stage viral maturation severely through IN multimerization. Induction of IN multimerization interferes with …

Chm116 Principles Of Chemistry Ii Lecture Slides, Leah S. Cohen, Probal Banerjee

Open Educational Resources

This file contains the lecture slides that are used in CHM116, Principles of Chemistry II.

Sustainable Methodologies For Synthesis Of Small Organic Molecules Using Micellar Catalysis., Deborah Sam Ogulu

Electronic Theses and Dissertations

Organic synthesis is a critical process in the creation of small molecule pharmaceuticals and agrochemicals. However, most methods for synthesizing these small molecules rely on toxic organic solvents as the reaction medium which account for approximately 80% of pharmaceutical waste. Moreover, many catalytic reactions require expensive endangered precious metals like palladium and costly metals. This dissertation presents research that aims to develop sustainable, eco-friendly reaction conditions to address these issues. We developed a ligand-free bimetallic nanocatalyst for the hydrogenation of unsaturated enones. This ligand-free nanocatalyst was prepared from nickel and ppm loading of palladium and was stabilized by harnessing the …