Organic Chemistry Commons^™

A Model For The Rapid Assessment Of Solution Structures For 24-Atom Macrocycles: The Impact Of Β-Branched Amino Acids On Conformation, Alexander J. Menke, Camryn J. Gloor, Liam E. Claton, Magy A. Mekhail, Hongjun Pan, Mikaela D. Stewart, Kayla N. Green, Joseph H. Reibenspies, Giovanni M. Pavan, Riccardo Capelli, Eric E. Simanek

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Experiment and computation are used to develop a model to rapidly predict solution structures of macrocycles sharing the same Murcko framework. These 24-atom triazine macrocycles result from the quantitative dimerization of identical monomers presenting a hydrazine group and an acetal tethered to an amino acid linker. Monomers comprising glycine and the β-branched amino acids threonine, valine, and isoleucine yield macrocycles G-G, T-T, V-V, and I-I, respectively. Elements common to all members of the framework include the efficiency of macrocyclization (quantitative), the solution- and solid-state structures (folded), the site of protonation (opposite the auxiliary dimethylamine group), the …

Synthesis And Analysis Of Novel Troponoid-Based Chemical Probes, Alex Berkowitz

Dissertations, Theses, and Capstone Projects

Troponoids are a class of non-benzenoid aromatic species featuring a cycloheptatrienone ring and varying degrees of oxygenation. These scaffolds have proven ubiquitous amongst natural products, and have displayed promise as therapeutic agents against a variety of diseases. Herein, we will describe our efforts towards furthering troponoids as potential pharmaceuticals. In Chapter 1, we outline a kojic acid-derived oxidopyrylium cycloaddition/ring-opening method developed in our lab to generate ahydroxytropolones (aHTs). This route was successfully adapted to synthesize a small library of lipophilic aHTs that were proven to be effective against herpes simplex virus-1 (HSV-1) replication, while providing further insight into the mechanism …

Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman

Dissertations

Most materials are closed shell in which every electron participates in a bond, resulting in unremarkable magnetometry signatures and functionalities. While rare, modern technologies rely on magnetic materials in which unpaired electrons are localized to inorganic atomic centers. In recent decades, a collection of organic open-shell π-conjugated molecules have shown magnetic ordering, albeit at exceedingly low temperatures; a result of weak noncovalent intermolecular interactions limiting long range electronic exchange. Thus, practically applicable sp orbital magnetism that persists at or above room temperature remains a grand challenge for chemistry and physics. Despite the wide variety of chemical structures afforded by organic …

Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, Elizabeth Mcgrew, Kevin M. Miller Phd

Posters-at-the-Capitol

Cellulose, an inexpensive and renewable biomacromolecule, represents an intriguing synthetic foundation for new materials with task-specific properties. Here, we wish to report a synthetic route for functionalizing cellulose with a side chain containing two ionic liquid functional groups using azide-alkyne ‘click’ cyclization strategy, followed by quaternization of the two resulting heterocycles (1,2,3-triazole and imidazole). Through this functionalization strategy, the resulting cellulosic materials exhibited significant softening, with several glass transition (T_g) values observed below room temperature, indicating the amorphous nature of the materials, with the T_g dependent on both the length of the side chain and the …

Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, A.M.Shashika D. Wijerathna, He Zhao, Qiangqiang Dong, Qixia Bai, Zhiyuan Jiang, Jie Yuan, Jun Wang, Mingzhao Chen, Markus Zirnheld, Rockwell T. Li, Yuan Zhang, Yiming Li, Pingshan Wang

College of Sciences Posters

Metal-organic macrocycles have received increasing attention not only due to their versatile applications such as molecular recognition, compounds encapsulation, anti-bacteria and others, but also for their important role in the study of structure-property relationship at nano scale. However, most of the constructions utilize benzene ring as the backbone, which restricts the ligand arm angle in the range of 60, 120 and 180 degrees. Thus, the topologies of most metallo-macrocycles are limited as triangles and hexagons, and explorations of using other backbones with large angles and the construction of metallo-macrocycles with more than six edges are very rare.

In this study, …

Trichloroethylene (Tce) Metabolite S-(1,2-Dichlorovinyl)-L-Cysteine (Dcvc) Inhibits Lps-Stimulated Cxcl-2 Production In Thp-1 Cells, Karena Moleakunnel, Audrey Luce, Lyric Johnson, Erica Boldenow, Sean Harris

Summer Research

• TCE is a volatile industrial solvent commonly found in the environment is known to be a "human carcinogen". However, its effects on gestational tissues and inflammatory pathways remain unknown. 1
• TCE inhibits various cytokines like IL-1b, IL-6, IL-8, and TNF-a.
• CXCL2 is a cytokine involved in the recruitment of neutrophils which serve as a key immune defense against infection. 3
• In past research, mice with the reduction of CXCL-2 showed reduced survival rates.
• Goal:• Analyze CXCL-2 production in THP-1 cells treated with DCVC • Understand how DCVC affects the cytokine pathway

Measuring Monoglyceride Densities Via Pycnometry, Lucas Postuma, Paul Harper

Summer Research

Glycerides are a type of lipid, and are comprised of a hydrophilic head group and one or more hydrophobic tail groups. Monoglycerides have glycerol head group, and one fatty acid chain as a tail group (Fig 1). They form interesting and complex structures/phases at different temperatures (Fig 2). Monoglycerides have many applications in drug delivery, protein crystallization scaffolds, and nanoscale templates (Seper et al). However, even though they are so ubiquitous, the measurements we have of monoglycerides such as monoolein are sparse in the literature, and the data that exist are contradictory; there is a need for systematic density measurements. …

Computational Modelling Of Cys-Tyr Containing Proteins, Alina Sainju, David Benson

Summer Research

Mammalian cysteine dioxygenase (CDO) is a non-heme iron enzyme that is known for catalyzing the conversion of cysteine (Cys) to Cysteine sulfinic acid (CSA) in the body. Cysteine is an essential amino acid needed in the body but if cysteine levels are not regulated and it gets too high then it can become toxic for the body. For this reason, CDO starts cysteine degradation and, therefore, CDO is important for cysteine level regulation. While it is known that CDO aids in cysteine regulation, the exact pathway mechanism of how it does so is still unclear. It is hypothesized that loss-of-function …

Synthesis Of Putative Microcystin-Lr Degradation Products And Full Macrocyclic Cyanopeptide, Mahesh Kumar Yadab

Wayne State University Dissertations

This thesis primarily focuses on synthesizing fragments of microcystin-LR, which is a natural product, with the aim of establishing them as analytical standards for investigating the biodegradation pathways of MC-LR. Despite of the substantial interest in synthesizing, isolating, and degrading Microcystins over the past few decades, the availability of high-purity microcystin standards at known concentration for quantitative analysis of using LC-MS/MS remains limited. The synthesis of the proposed MC-LR fragments employs the Fmoc/t-Bu protecting group strategy to prevent isomerization. Additionally, novel methods for the total synthesis of N-Boc-Adda are explored, incorporating atom-economic approaches, cross-metathesis, and oxidative boron Heck reactions. The …

High Order Structures Formed By The Natural Aromatic Amino Acids, Gabriel Alexander Kupovics, Zeina Alraawi

Inquiry: The University of Arkansas Undergraduate Research Journal

Excessive concentrations of the natural aromatic amino acids phenylalanine and tyrosine are characteristic of the severe genetic abnormalities known as phenylketonuria (PKU) and tyrosinemia, respectively. Within this context, this feature article authenticates claims that tryptophan can form amyloid-like supramolecular structures in vitro and is the first to propose potential mechanisms of tryptophan self-assembly, including hydrophobic and electrostatic interactions. Thioflavin T (ThT) fluorescence kinetics and transmission electron microscopy (TEM) data suggest the formation of amyloid-like fibrillar structures by natural aromatic amino acids in vitro. Additionally, the propensity of amino acid aggregation increases in the presence of sodium dodecyl sulfate (SDS). The …

Structural And Functional Modulation Of Metal-Organic Supercontainers (Moscs) And Their Applications In Supramolecular Catalysis, Shrijana Dc

Dissertations and Theses

Metal-organic supercontainers (MOSCs), a breakthrough development in our laboratory since 2012, have emerged as promising enzyme mimics, showcasing their prowess in encapsulating guest molecules and catalyzing confined chemical reactions. The intrigue surrounding MOSCs stems from their extraordinary traits, encompassing multiple binding domains, high stability, large surface area, tunable pore size, and structural modularity. Primarily comprising sulfonylcalix[4]arenes, divalent metal ions, and carboxylate linkers, MOSCs' quintessential architecture comprises both endo- and exo- nano-cavities, amenable to guest interaction, with geometry and functionality manipulation achievable through precise precursor selection. Nonetheless, early MOSC models exhibit limited reactivity, often necessitating more potent nucleophiles or electrophiles. This …

Green And Non-Green Extraction Of Eugenol From Cloves Using Steam Distillation, Bek Yuldashbaev

Science University Research Symposium (SURS)

Eugenol is commonly found in many plants such as cloves. It is one of the most used natural anesthetics in dentistry. Indonesia is one of the places indigenous to clove trees. Its people take advantage of the pain numbing properties in cloves to aid their tooth pain. The extraction of eugenol itself can be performed through steam distillation. With the process of distillation, the steam carries the oils extracted from the clove buds and recondenses into a cloudy distillate containing polar and non-polar molecules. To separate the eugenol from the distillate, green and non-green solvents were used. The green solvent …

Extracting High-Molecular Weight Dna From Cyanobacteria Using Promega's Wizard® Hmw Dna Extraction Kit With A Modified Protocol, Metis, Megan A. Hept, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Extraction of high molecular weight (HMW) DNA for long read sequencing with little to no fragmentation and high purity is difficult to acquire from cyanobacterial species. Here we describe a modified method of extraction using Promega's Wizard® HMW DNA Extraction Kit to acquire high molecular weight DNA from cyanobacterial species. The protocol used in the kit is the “3.D. Isolating HMW DNA from Gram-Positive and Gram-Negative Bacteria” protocol. During a key step in the protocol, the lingering remnants of the mucilage layer of the cyanobacterial species is removed, preventing it from sticking to the DNA pellet produced. This customized modification …

Abiotic Stress Mitigation: A Case Study From 21 Trials Using A Natural Organic Matter Based Biostimulant Across Multiple Geographies, Rachel L. Sleighter, Terry Hanson, David Holden, Kristen M. Richards

Chemistry & Biochemistry Faculty Publications

Crop productivity and yields can be greatly diminished by abiotic stress events including drought, extreme temperatures, excess moisture, and saline irrigation water. Multiple stressors occurring simultaneously can further exacerbate the strain on plants. Various types of biostimulants have been shown to mitigate abiotic stress and here, the results of 21 trials on corn, wheat, soybean, and various high-value crops are discussed in the context of the abiotic stress that either occurred naturally or was experimentally induced. Treatments in these trials included stressed and non-stressed plants, as well as either an untreated control or grower standard fertilizer applications alone and in …

Development And Biological Evaluation Of Selective Small-Molecule Inhibitors Of The Human Cytochrome P450 1b1, Austin Hachey

Theses and Dissertations--Chemistry

The human cytochrome P450 1B1 (CYP1B1) is an emerging target for small- molecule therapeutics. Several solid tumors overexpress CYP1B1 to the degree that it has been referred to as a universal tumor antigen. Conversely, its expression is low in healthy tissues. CYP1B1 may drive tumorigenesis through promoting the formation of reactive toxins from environmental pollutants or from endogenous hormone substrates. Additionally, the expression of CYP1B1 in tumors is associated with resistance to several common chemotherapies and with poor prognoses in cancer patients. However, inhibiting CYP1B1 with small molecules has been demonstrated in cellular and murine model systems to reverse this …

Discovery Of Acetyl Coa Synthetase And Sars-Cov-2 Protease Inhibitors, Taiwo Elijah Esan

Graduate Research Theses & Dissertations

There is an urgent need for new antifungal drugs. Acetyl CoA synthetases (ACSs) are Acyl-CoA/NRPS/Luciferase (ANL) superfamily enzymes that couple acetate with CoA to generate acetyl CoA, a key component of central carbon metabolism in eukaryotes and prokaryotes. Normal mammalian cells are not dependent on ACSs, while tumor cells, fungi, and parasites rely on acetate as a precursor for acetyl CoA. Consequently, ACSs have emerged as a potential drug target. This body of work focuses on the inhibition of the Acetyl CoA synthetase enzyme in fungal species. This work has involved designing and synthesizing compounds that are potential fungal ACS1 …

The Discovery And Characterization Of Novel Potent 5-Substituted 3, 3’, 4’, 7-Tetramethoxyflavonoid Dna Triplex Specific Binding Ligands, Vanessa Marie Rangel

University of the Pacific Theses and Dissertations

Chemotherapy works by killing fast dividing cells. Unfortunately, these drugs are not specific to cancer tissue and can damage normal cells. Chemotherapy is like taking poison and hoping it kills the cancer cells before it kills you. As an alternative, many researchers have investigated the use of antigene therapy to selectively target cancer causing genes to avoid off target effects. Although promising, the theory is limited by the stability of the triplex structure. Here, we report the discovery of potent triplex binding ligands derived from the natural product quercetin. Chemical derivatives of 5-substituted 3, 3’, 4’, 7-tetramethoxyquercetin derivatives were characterized …

Design, Synthesis, And Evaluation Of Acetyl Coa Synthetase Inhibitors, Michael Emmett Heene

Graduate Research Theses & Dissertations

Invasive fungal species provide a challenge to the current drug landscape, only partiallymet by approved drugs. The Acetyl Coenzyme Synthetase (ACS) enzymes are an attractive target for antifungal compounds because normal mammalian cells do not rely on ACS for energy metabolism while fungal cells do rely on ACS. This work focuses on the design and synthesis of inhibitors of various fungal ACS enzymes. The first class of inhibitors is based on the 2-aminothiazole scaffold originating from a saturation transfer difference (STD) nuclear magnetic resonance (NMR) study and previous whole-organism assays. Ultimately, the 2-aminothiazole core compounds were found to not be …

Investigation Of Factors Affecting Reverse-Phase High Performance Liquid Chromatography, Rida A. Syed

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

This study focused on the application of reverse-phase high-performance liquid chromatography (RP-HPLC). RP-HPLC is used for the purification of organic molecules, including pharmaceuticals, natural products, and proteins. We developed a modified version of a United States Pharmacopeia (USP) procedure to separate and purify the chemical components found in Excedrin tablets. The goal was to investigate the relationship between retention time (Tr) and the capacity factor (k') of solutes. By varying the composition of the mobile phase and stationary phase, we experimentally determined the capacity factor of acetaminophen (APAP), caffeine, and aspirin. Our results show that the capacity factor (k') of …

Synthetic Studies Of Dragonamide E And Its Potential Treatment Of Leishmaniasis, Sarah E. Glaesemann

Chemistry Theses

Leishmaniasis is a parasitical infection categorized as one of about twenty Neglected Tropical Diseases. Spread by the female sand fly, it can become very severe if left untreated. Symptoms include skin lesions, which may cause scarring, and mucosal membrane infection, which may lead to facial deformity. The most severe form of leishmaniasis can infect organs such as the liver and spleen, possibly leading to death. The current treatments for leishmaniasis are becoming limited due to an increase in drug resistant parasites. Furthermore, the side effects of these treatments can be very problematic.

In the search for new treatments for tropical …