Organic Chemistry Commons^™

Stereocontrolled Synthesis Of Lactam-Fused Tetrahydropyrans As Potential Antidiabetic Agents, Ifeyinwa Stella Anosike

All Master's Theses

Functionalized tetrahydropyrans are structural motifs in diverse natural products, including polyether antibiotics, marine toxins, pheromones, and pharmaceuticals. They are frequently used as versatile building blocks for accessing stereochemically sophisticated biologically active compounds. Specifically, functionalized bicyclic tetrahydropyrans bearing contiguous stereocenters have garnered interest in the synthesis and medicinal chemistry communities. Thus far, some synthetic methods have been developed for their construction and functionalization. These methods include Prins' cyclization reactions, intramolecular oxa-Michael reactions, hetero-Diels-Alder cyclization, ring-closing metathesis, radical cyclization, and halocycloetherification. However, these methods have some drawbacks such as the need for expensive reagents and catalysts, substrate limitations, and environmentally unfriendly conditions. …

Chemical Synthesis Of Sensitive Dna, Komal Chillar

Dissertations, Master's Theses and Master's Reports

Over the past decades, researchers have tried various chemical methods to synthesize modified oligodeoxynucleotides (ODNs, i.e. short segments of DNAs). Traditional ODN synthesis methods require strong basic, and nucleophilic conditions for the deprotection and cleavage of the ODN from the solid support. However, the sensitive ODNs containing labile functionalities are vulnerable to such harsh conditions. Sensitive ODNs have a wide range of applications in research and pharmaceuticals. To synthesize sensitive ODNs, researchers devised different strategies but no practical methods have been developed. To overcome these challenges, we developed alkyl Dim alkyl Dmoc technology. This innovative technology uses weakly basic and …

Establishing A Two-Color Fluorescence Probe Assay For The Simultaneous Screening Of Glut5 And Glut2 Fructose Transporters In Live Cells, Oluwanifesimi Mary Afolabi

Dissertations, Master's Theses and Master's Reports

The mammalian facilitative glucose transporter (GLUT) family comprises 14 members that mediate the transport of hexoses across cell membranes. GLUT5 is the only member specific to fructose, and together with GLUT2, which transports fructose in addition to glucose, they make up the primary fructose transporters in humans. This study introduces a novel two-color fluorescence assay designed to simultaneously monitor the activity of GLUT5 and GLUT2 in live cells. 2,5-anhydro-D-mannitol (2,5-AM) a GLUT5 targeting compound has facilitated the development of various fructose-mimicking probes with a wide range of properties, such as radioactive imaging, fluorescent, photoactive, and drug delivery capabilities. Effective and …

Synthesis Of Long Oligodeoxynucleotides, Yipeng Yin

Dissertations, Master's Theses and Master's Reports

Synthetic long oligodeoxynucleotides (ODNs) have found wide applications in diverse fields such as chemical biology, synthetic biology, and genes and genomes synthesis. Those applications leading to a significant demand for their production. However, traditional methods for purifying synthetic ODNs present notable drawbacks, particularly their inability to purify long ODNs, rendering long ODN synthesis challenging. To address these issues, chemical synthesis techniques for long ODNs coupled with non-chromatographic purification methods have been developed. This technology makes the purification of long synthetic ODNs feasible and offers a viable pathway for producing genes and genomes with extensive repeats or stable secondary structures, which …

The Investigation Of The Antimicrobial And Biofilm-Disrupting Properties Of Synthesized Hemibastadin Derivatives, Antonio Harvey, Andrew A. Yeagley

Longwood Senior Thesis Proposal

We want to investigate structural changes to the core hemibastadin structure while attempting to make these derivatives biologically safer. Since these modifications have never been done before, we will need to design a synthesis of these new molecules. Due to the nature of the molecules (dimers), a divergent synthesis that allows for the creation of both halves simultaneously seems most appropriate. A successful synthesis of these compounds will allow us to further investigate these derivatives for their antimicrobial and biofilm-disrupting properties.

Covalent Inhibition Of Enzyme Sortase A As A New Pathway Against Bacterial Resistance Of Staphylococcus Aureus, Umyeena Bashir

Master's Theses

The continued rise of antibiotic-resistant bacteria, such as MRSA (methicillin-resistant Staphylococcus aureus), has made the discovery of novel antibiotics critical. While bacteriostatic and bactericidal antibiotics inevitably exert evolutionary pressure on bacteria to develop resistance, small molecules that target mechanisms of bacterial virulence present a promising alternative for treatment. Sortase A (Srt A), a cysteine protease of S. aureus, promotes bacterial virulence by covalently attaching proteins such as pilin to the bacterial surface, enabling bacterial adhesion to mammalian cells. Inhibitory studies of this enzyme have gained prominent interest as a new pathway for drug development since blocking this enzyme's ability to …

Optimization Of Transition-Metal Inclusive Carbon Aerogels For Electrochemical Energy Applications, Allen Dalton Davis

Electronic Theses & Dissertations

The ever-growing need for energy alongside rising concerns for climate change demands the development of renewable energy technologies. Hydrogen fuel cells are a promising technology that can serve to either supplement energy generation or act as a lone power source. Yet for these devices to be truly green, the hydrogen that serves as fuel must be procured from a renewable resource. Electrolytic water splitting is a process that allows for the dissociation of water into H₂ and O₂. For this process to be practical, the electrolyzer needs to demonstrate high efficiency and stability, as well as a …

Exploring Soybean Oil-Based Polyol And Effect Of Non-Halogenated Flame Retardants In Rigid Polyurethane Foam, Sahithi Kondaveeti

Electronic Theses & Dissertations

To address the increasing demand for sustainable biomaterials due to the depletion of fossil fuel resources and growing environmental concerns, a new type of biodegradable and environmentally friendly rigid polyurethane foam (RPUF) has been synthesized. These foams are derived from chemically modified soybean oil-based polyol obtained from soybean oil by epoxidation followed by a ring-opening reaction. Polyurethane foam is generally used in construction, furniture, and automobile industries but is highly flammable and releases toxic gases and smoke during combustion. In this study, a highly efficient synergistic effect halogen-free flame-retardant (FR) melamine salt, 2-carboxyethyl(phenyl)phosphinic acid melamine salt (CMA) was synthesized from …

Enhanced Mechanical Strength Of Soybean Oil-Based Non-Isocyanate Polyurethane Adhesive For Wood Application By Introducing Nanofillers, Vatsal Chaudhari

Electronic Theses & Dissertations

Polyurethane (PU) is a versatile material that finds extensive use in various industries including bedding, construction, automotive, and packaging. Historically, this particular polymer relied significantly on petrochemical resources, a practice that was considered to have negative environmental impacts. The conventional method for preparing PU involves the use of isocyanate, which is a disadvantage due to its negative impact on the environment and human health. The resolution of this problem entails identifying an appropriate substitute for petroleum-derived products that minimize their impact on both the environment and human health. The researchers earlier utilized soybean oil, for the formulation of PUs in …

Castor Oil Polyol-Based Adhesives With Additional Crosslinker For Improvement In Mechanical And Thermal Properties., Yash Desai

Electronic Theses & Dissertations

Polyurethanes (PU) have been promising polymeric materials with many applications, including adhesives. Projecting an estimated revenue from 42.8 billion $ in 2021 to 61.5 billion $ by 2026. However, a large number of PU adhesives are sourced from petroleum products. Therefore, to lower the dependence on non-renewable resources and provide sustainable and affordable alternatives. In this work will synthesize bio-based adhesives of polyurethane from modified castor oil-based polyol. Generally, polyurethane reaction depends on the properties of polyol and isocyanates. The most important aspect of these reactions is the OH number of the polyol, which is responsible for the crosslinking and …

High Temperature Materials From Bis-Ortho-Diynylarene (Boda)-Derived Resins And Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers, Ernesto Isaac Borrego

Theses and Dissertations

This work expands the current understanding of materials chemistry and engineering capabilities of two synthetic platforms: 1.) bis-ortho-diynylarenes (BODA) and 2.) trifluorovinylaryl ethers (TFVE). Each platform possesses a unique chemistry which paradoxically enables the development of high-performance materials therefrom while simultaneously retaining exceptional melt and solution processability. Leveraging the apparent dichotomy in properties (performance/processability) obtainable from these two synthetics platforms, we have pursued and achieved a practical approach to high-temperature resistant materials with an immense potential for technology transfer and commercialization:

1.) BODA-derived resins (BDR) constitute a versatile platform of melt-processable resins capable of rapidly producing high performance …

Synthesis And Characterization Of Colorimetric And Flurometric Chemosensor For Trivalent Metal Ions, Fazila Haque

Honors Program Theses and Research Projects

There are many biological and environmental uses for trivalent metals (like Fe3+, Al3+, and Cr3+) within our daily lives. Whether these trivalent metals are found in deficiency or excess can cause issues within our environment (global warming) or our bodies (can cause problems with our digestive, cardiovascular, and immune systems). Being able to detect them and understanding their importance becomes crucial in our understanding of the world that surrounds us.
/="/">One of the ways we can detect these trivalent metals is through the use of chemosensors. Chemosensors are used to sense analyte (trivalent metal) to produce a signal (fluorescence …

Thermocatalytic Plasma-Assisted Dry Reforming Of Methane Over Ni/Al2o3 Catalyst, Tyler Wong

Seton Hall University Dissertations and Theses (ETDs)

Plasma catalysis is an advantageous approach that combines the effects of plasma with the enhancements of a catalyst. By utilizing a nickel catalyst in the plasma discharge zone of a dielectric barrier discharge (DBD), it can give an enhancement to the electrical field, boost microdischarges, and increase conversion and selectivity rates of CH₄ and CO₂ in the dry reforming of methane (DRM) reaction.

Industrial application of nickel catalysts in DBD Plasma DRM process are limited by poor stability, which is caused by the sintering of active metal particles and coke deposition on the catalyst surface. In this work, …

Beyond N-Dopants For Organic Semiconductors: Use Of Bibenzo[D]Imidazoles In Uv-Promoted Dehalogenation Reactions Of Organic Halides, Kan Tang, Megan R. Brown, Chad Risko, Melissa K. Gish, Garry Rumbles, Phuc H. Pham, Oana R. Luca, Stephen Barlow, Seth R. Marder

UK CARES Faculty Publications

2,2’-Bis(4-dimethylaminophenyl)- and 2,2'-dicyclohexyl-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[d]imidazole ((N-DMBI)2 and (Cyc-DMBI)2) are quite strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced bond-cleavage reactions, specifically dehalogenations. The dimers reduce halides that have reduction potentials less cathodic than ca. −2 V vs ferrocenium/ferrocene, especially under UV photoexcitation (using a 365 nm LED). In the case of benzyl halides, the products are bibenzyl derivatives, whereas aryl halides are reduced to the corresponding arenes. The potentials of the halides that can be …

Rapid Reaction Studies On The Chemistry Of Flavin Oxidation In Urocanate Reductase, Niusha Delavari

Masters Theses

Urocanate reductase (UrdA) is a bacterial flavin-dependent enzyme that reduces urocanate to imidazole propionate, enabling bacteria to use urocanate as an alternative respiratory electron acceptor. Elevated serum levels of imidazole propionate are associated with the development of type 2 diabetes and, since UrdA is only present in humans in gut bacteria, this enzyme has emerged as a significant factor linking the health of the gut microbiome and the metabolic disorder insulin resistance. Here we investigated the chemistry of flavin oxidation by urocanate in the isolated FAD domain of UrdA (UrdA’) using anaerobic stopped-flow experiments at 4 °C. This analysis unveiled …

Deficiency Of Acute-Phase Serum Amyloid A Exacerbates Sepsis-Induced Mortality And Lung Injury In Mice, Ailing Ji, Andrea C. Trumbauer, Victoria P. Noffsinger, Luke W. Meredith, Brittany Dong, Qian Wang, Ling Guo, Xiangan Li, Frederick C. De Beer, Nancy R. Webb, Lisa R. Tannock, Marlene E. Starr, Christopher M. Waters, Preetha Shridas

Saha Cardiovascular Research Center Faculty Publications

Serum amyloid A (SAA) is a family of proteins, the plasma levels of which may increase >1000-fold in acute inflammatory states. We investigated the role of SAA in sepsis using mice deficient in all three acute-phase SAA isoforms (SAA-TKO). SAA deficiency significantly increased mortality rates in the three experimental sepsis mouse models: cecal ligation and puncture (CLP), cecal slurry (CS) injection, and lipopolysaccharide (LPS) treatments. SAA-TKO mice had exacerbated lung pathology compared to wild-type (WT) mice after CLP. A bulk RNA sequencing performed on lung tissues excised 24 h after CLP indicated significant enrichment in the expression of genes associated …

Synthesis Of Bacterial Glycerophospholipids For Biomembrane Model Studies: A Means To Advanced Biofuels, Felix Adulley

Electronic Theses and Dissertations

To reduce reliance on fossil fuels, sustainable biofuels are being pursued, especially advanced biofuels like 1-butanol that have higher energy content and greater compatibility with existing infrastructure than ethanol. A persistent challenge is the yield-limiting toxicity of biofuels and process solvents, such as tetrahydrofuran, to the microbes that ferment biomass into biofuel. The cell membrane is a focal point of toxicity, and understanding how it interacts with fuels and solvents is key to improving yield. Phospholipid bilayers are the core of biomembranes, and model biomembranes of defined composition provide the ideal platform for biophysical studies. To this end, glycerophospholipids characteristic …

Chemical Investigation Of Dichloromethane Extract Of Aloe Vera Peels: An Agricultural Waste, Nazmul Huda

Theses and Dissertations

Aloe barbadensis Miller, commonly called Aloe Vera, is a widely popular succulent plant species cultivated across subtropical regions worldwide from India to the Tex-Mex border. Besides its historical uses, Aloe juice has garnered attention as a potential remedy for various ailments, particularly in treating various skin conditions and facilitating wound recovery, including obesity, diabetes, hepatitis, Crohn's disease, and ulcerative colitis. Regrettably, the agricultural practice following sap extraction involves discarding Aloe vera peels, constituting agricultural waste. As part of our continuous research on extraction, isolation, separation, and spectral characterization of value-added chemicals present in waste botanicals herein, …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

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 …