Organic Chemistry Commons^™

Oxidation Of Thiols To Disulfides Using An Environmentally “Green” Organocatalyst And New Mechanistic Insights, Kosta V. Vlasakakis, Olivia M. White, Robert P. Reynolds, Shayne M. Weierbach, Shannon M. Weaver, Ramsey T. Ritter, Nishi H. Patel, Eric C. Hayes, Sydney Dunmire, Kyle M. Lambert

Undergraduate Research Symposium

The selective oxidation of thiols to disulfides is an area of great importance in the areas of materials and medicinal chemistry research. The production of polymers, rubber, pharmaceuticals, and the folding of proteins in biological systems all rely on the formation of disulfide bonds. Herein, we introduce a stoichiometric and electrocatalytic method for the oxidation of various pharmaceutically and biologically relevant thiols into their respective disulfides in more environmentally benign solvents such as water and alcohol solvents. The scope of the transformation was evaluated and a detailed mechanistic study involving control experiments, experimental kinetic studies, and computational investigations led to …

The Synthesis And Biocatalytic Reduction Of Beta-Keto Alkynes, Rhema M. Francis

College of Graduate Studies: Theses & Dissertations

The preparation of enantiopure homopropargyl alcohols (but-3-yn-ols) is of high importance to the scientific community. They are employed as valuable pharmaceutical intermediates and are opportune to generate antiviral nucleoside analogues. Chiral inducement of these molecules thus far has been poor (low ee) and has constituted a key challenge for asymmetric synthesis in the last few decades. Enzyme-catalyzed enantioselective reductions of ketones have become popular to produce thus-prepared synthons on an industrial scale. Among them, biocatalysts (dehydrogenases, reductases) emerge as a biodegradable option for chemical transformations, in comparison to chiral catalysts that employ highly toxic metals. This research investigates the catalytic …

Synthesis Of 6,6- And 7,7-Difluoro-1-Acetamidopyrrolizidines And Their Oxidation Catalyzed By The Nonheme Fe Oxygenase Lolo, Nabin Panth

Theses and Dissertations--Chemistry

One of the remarkable steps in loline alkaloid biosynthesis is the installation of an ether bridge between two unactivated C atoms in 1-exo-acetamidopyrrolizidine (AcAP). LolO, a 2-oxoglutarate-dependent nonheme Fe oxygenase, catalyzes both the hydroxylation of AcAP and the resulting alcohol's cycloetherification to give N-acetylnornoline (NANL). The mechanism of hydroxylation is well understood, but the mechanism of the oxacyclization is not. I synthesized difluorinated analogs of AcAP in an attempt to further understand the mechanism of the unusual cycloetherification step.

I prepared 6,6-F₂-AcAP in eight steps from N,O-protected 4-oxoproline. The key step was a Dieckmann …

Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk

Dissertations, Theses, and Capstone Projects

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism …

Recent Studies On The Synthesis Of Medicinal Molecules., Paige Monsen

Electronic Theses and Dissertations

Medicinal chemistry interfaces synthetic organic chemistry, natural product chemistry and chemical biology, with a goal of yielding therapeutic agents. Natural products or compounds derived from natural sources such as plants, animals, and microorganisms, are often biologically active and render that compound a likely drug lead. For thousands of years humankind has utilized natural products for medicinal purposes and consequently scientists take advantage of both these compounds’ core structural characteristics and their modes of actions on selected targets as inspiration to develop therapeutics. Because the total synthesis of such complex molecules can be cumbersome and expensive, semi-synthetic methods on isolated natural …

Design Of Antioxidant Monomer, Augustine Osilamah Yusuf

Masters Theses & Specialist Projects

Reactive oxygen species such as hydrogen peroxide are present at the sites of inflammation in the body. Degradable polymeric nanoparticles have shown great promise in a range of biomedical applications which include preferential delivery of therapeutics to such inflamed sites. We are working towards a new class of materials expected to have tunable degradation rates in the presence of hydrogen peroxide. These new materials consist of three parts: degradable linkages, antioxidant groups, and unreactive filler monomers such as methylmethacrylate. We have synthesized a polymerization initiator with a degradable linkage, and we have shown that using this initiator to synthesize another …

Design, Synthesis And Evaluation Of Molecules With Selective And Poly-Pharmacological Actions At D1r, D3r And Sigma Receptors, Pierpaolo Cordone

Dissertations, Theses, and Capstone Projects

The dopamine D3 receptor (D3R) is one of the most studied receptors involved in drug addiction. One of the most common strategies to treat substance use disorders is via D3R antagonism. The majority of the D3R antagonists synthesized so far have poor pharmacokinetic properties and/or lack selectivity toward D3R. In this thesis, the design, synthesis and biological evaluation of novel molecules that target the dopamine D1 receptor (D1R), D3R and the serendipitous discovery of molecules that target s receptors will be described.

Chapter 1 presents a survey of the fundamental pharmacology of D1R, D3R and s receptors and the therapeutic …

Synthetic And Biological Studies On Benzazepine Derivatives As Dopamine Receptor Ligands, Rajan Giri

Dissertations, Theses, and Capstone Projects

Dopamine (DA) receptors, members of the G-protein coupled receptors (GPCRs) family, are divided in two groups based on their transmembrane structural homology domains: D1R-like (D1R, D5R sub-types) and D2R-like DA receptors (D2R, D3R and D4R sub-types). Disturbances in dopaminergic neurotransmission are associated with several CNS disorders. Hence, DA receptor selective ligands have been sought as pharmacological agents to normalize perturbations in the dopaminergic system. Despite several notable efforts, the discovery of highly selective ligands for dopamine receptor sub-types has proved challenging due to close transmembrane structural similarity, especially between DA receptor sub-types within the same group.

The 1-phenylbenzazepine scaffold is …

The Emerging Applications Of Sulfur (Vi) Fluorides In Catalysis, Nicholas Ball, Cayo Lee, Jonathan E. Elisabeth, Nathan C. Friede, Glenn M. Sammis

Pomona Faculty Publications and Research

The past decade has witnessed remarkable growth of catalytic transformations in organic sulfur(VI) fluoride chemistry. This Perspective concentrates exclusively on foundational examples that utilize catalytic strategies to synthesize and react S(VI) fluorides. Key mechanistic studies that aim to provide insight toward future catalytic systems are emphasized.

Advancing The Preclinical Development Of Secondary Metabolites From Cacospongia Mycofijiensis For The Treatment Of Cancer, Joseph Morris

Natural Sciences and Mathematics | Biological Sciences Master's Theses

The marine sponge Cacospongia mycofijiensis from the Indo-Pacific has proven to be a source of structurally diverse secondary metabolites that are biologically active against a variety of distinct targets. Current interest in the secondary metabolites of C. mycofijiensis largely stems from a) their potent and preferential cytotoxicity for cancer cell lines versus normal cells, making many of them promising leads as cancer therapeutics and b) the novel mechanisms of action responsible for their impressive cytotoxicity. However, limited compound availability has resulted in a paucity of studies aimed at advancing the preclinical development of these secondary metabolites from C. mycofijiensis for …

Reeling In New Antibiotics: Synthesis And Antimicrobial Susceptibility Testing Of Zinc-Binding Clavanins From Styela Clava (Sea Squirt), Eduardo Badillo-Colberg

Honors Scholar Theses

Clavanins have been a quite rarely studied antimicrobial peptide (AMP) family. Though the data in the few studies published on the matter and in theoretical experimental data presented by the Wang lab in their peptide library creation [14], in that the members of this family could potentially be quite effective novel antimicrobial candidates. Among those that have been targets of studies, Clavanin A has been at the forefront of this endeavor of finding effective novel antimicrobial peptides[14]. In these aforementioned studies, Clavanin A has been shown to be quite effective against many different bacterial strains, which begs the question as …

Synthesis Of Bulky And Polar Galactonoamidines For The Inhibition Of The Human Α-Galactosidase, Ifedi Orizu

Graduate Theses and Dissertations

Glycosidases are amongst the most abundant enzymes in nature. This is due to their role in the degradation of carbohydrates which are the major source of carbon or earth. The absence or malfunction of glycosidases is implicated in numerous diseases such as cancers, diabetes, and lysosomal storage disorders, which make them important drug targets for study in medicinal chemistry. The seminal work by Pauling and Wolfenden showed that enzymes bind to their substrate at the transition state with very strong affinity. Wolfenden estimated the dissociation constant to be around 10-22M. This encouraged the design of glycosidase inhibitors which mimicked one …

Theranostic Nanoparticles Folic Acid-Carbon Dots-Drug(S) For Cancer, Godwin Kweku Babanyinah

Electronic Theses and Dissertations

This study aims to prepare theranostic nanoparticles (NPs) that are expected to increase cancer diagnostics and therapeutic efficacy. We prepared the NPs constituting carbon dots (CDs) as an imaging agent, folic acid as a targeting agent, doxorubicin (DOX), or gemcitabine (GEM) as chemotherapy agents. The NPs include noncovalent FA-CDs-DOX, covalent CDs-FA-DOX, and covalent FA-CDs-GEM. Through ultraviolet-visible spectroscopy, fluorescence spectroscopy, and Fourier transform-infrared spectroscopy, the fabrication of these NPs was confirmed. It was discovered that the high drug loading efficiency is the noncovalent series while the high drug loading capacity is the covalent series The in-vitro pH-dependent drug release data indicate …

Convergent Synthesis Of Anaephene B, Megan Johnson

Honors Program Theses

Many organisms are capable of producing organic compounds as secondary metabolites; these natural products can be quite pharmaceutically and medicinally relevant.1 Typically, the more unique an organism, the more unique its secondary metabolites. Cyanobacteria, an abundant microalgal organism, is capable of producing a myriad of novel natural products.2 The unique photosynthetic and autotrophic properties of cyanobacteria allow for the production of many secondary metabolites, including lipopeptides, amino acids, fatty acids, macrolides, amides, and others.2,3 Staphylococcus aureus is one the most common bacterial infections in the world.4 S. aureus produces a number of metabolites that inhibit host immune responses.4 As a …

Fine-Tuning Of Molecular Structures To Generate Carbohydrate Based Super Gelators And Their Applications For Drug Delivery And Dye Absorption, Jonathan Bietsch, Mary Olson, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based low molecular weight gelators (LMWGs) exhibit many desirable properties making them useful in various fields including applications as drug delivery carriers. In order to further understand the structural connection to gelation properties, especially the influence of halide substitutions, we have designed and synthesized a series of para-chlorobenzylidene acetal protected D-glucosamine amide derivatives. Fifteen different amides were synthesized, and their self-assembling properties were assessed in multiple organic solvents, as well as mixtures of organic solvents with water. All derivatives were found to be gelators for at least one solvent and majority formed gels in multiple solvents at concentrations lower than …

Enabling Technologies For Medicinal Chemistry And Synthesis: I. Cannabinoids; Ii. Illudalic Acid; Iii. Microwave Chemistry, Harvey Fulo

Graduate Theses, Dissertations, and Problem Reports (ETD)

Innovations in synthetic organic chemistry such as methodology improvements, new chemical transformations and technology development significantly impact medicinal chemistry and continue to drive the drug discovery process. Here, new cyclization strategies to the pharmaceutically underexplored 3,3-dimethylcyclopentane-fused aromatic rings are described. One approach highlighted oxidative cycloisomerization, intermolecular [2+2+2] cyclotrimerization and 5-exo-dig cyclization providing indanoylindole cannabinoids that possess high affinity for human CB₂ receptors at nanomolar concentration and good selectivity index. Another featured a [4+2]-type benzannulation reaction which enabled the 5-step synthesis of illudalic acid — compared to the current available sequences (≥16 steps) — and its equipotent and LAR-selective analogs. …

Biocompatible And Multifunctional Trityl Spin Probes For Electron Paramagnetic Resonance Spectroscopy, Teresa D. Gluth

Graduate Theses, Dissertations, and Problem Reports (ETD)

The primary objective of my thesis was to develop and utilize a biocompatible multifunctional trityl spin probe for concurrent measurement of pO₂, pH_e, and [P_i] in vivo by electron paramagnetic resonance (EPR) spectroscopy (Chapter 2). My first goal was to synthesize the proposed probe we are terming HOPE71. Secondly, HOPE71 was characterized by X-band and L-band EPR spectroscopy. Next, the biocompatibility of HOPE71 was assessed through an albumin binding test, cytotoxicity assays, and in vivo intravenous tolerance. Then, the use of HOPE71 to measure the target parameters was demonstrated in a breast cancer …

Synthesis Of Dual Small Molecule Hybrids To Probe The Synergy Between Dna Repair Enzymes And Ido1, Nathaniel George

Theses and Dissertations--Chemistry

Indoleamine 2 3-dioxygenase (IDO) has recently been highlighted as a promising target for small molecule based immunotherapy. IDO is often coopted by various cancer cells to promote an immune-suppressive environment around tumors. DNA damage repair (DDR) enzymes have recently been targeted for inhibition to promote genetic instability and bolster immune recognition. DDR enzymes such as PARP and POLγ are common inhibition targets due to their direct effects on cellular function. In the process of designing conjugate inhibitors of IDO and DDR enzymes, novel synthetic methodology was developed for the mild deprotection of N-Tert-butyloxycarbonyl (N-BOC) group from various amines. Conjugate …

Design And Synthesis Of Targeted Immunotherapeutic Agents, Md Shohel Rana

Graduate Theses, Dissertations, and Problem Reports (ETD)

The therapeutic monoclonal antibodies are very important tools to fight against the diseases especially in the field of cancer immunotherapy. Many immunotherapeutic antibodies are being used to treat cancer that target multiple different components of the cancer microenvironment. Cells with extracellular juxtacrine ligands [JL-cells] and extracellular juxtacrine receptors [JR-cells] form JL-cell-JR-cell interfaces that produce juxtacrine signals inside JR-cells. [76] Juxtacrine signaling unlike endocrine or paracrine signaling requires no release or cellular uptake of ligands. [76] Immune checkpoint inhibitors are soluble IgG antibodies that block juxtacrine ligand engagements with juxtacrine receptors on tumor or other immune cells. [77] Rapid Nobel Prize …

Melanogenesis, Its Regulatory Process, And Insights On Biomedical, Biotechnological, And Pharmacological Potentials Of Melanin As Antiviral Biochemical, Toluwase Hezekiah Fatoki, Omodele Ibraheem, Catherine Joke Adeseko, Boluwatife Lawrence Afolabi, Daniel Uwaremhevho Momodu, David Morakinyo Sanni, Jesupemi Mercy Enibukun, Ibukun Oladejo Ogunyemi, Akinwunmi Oluwaseun Adeoye, Harriet U. Ugboko, Amoge Chidinma Ogu, Abiodun Samuel Oyedele, Adejoju Omodolapo Adedara, Abiodun Joseph Jimoh, Oluwakemi Ruth Ogundana, Oritsetimeyin Eworitse Ebosa

Chemistry Student Research

Melanin is s most widely distributed pigment and is found in bacteria, fungi, plants, and animals. Melanogenesis is under complex regulatory control by multiple agents interacting through pathways activated by hormonal and receptor-dependent and -independent mechanisms. There are about 20 genes that are involved in the biochemical pathway of melanogenesis and its regulation, which include: tyrosinase, microphthalmia-associated transcription factor, melanocortin1 receptor, adenylate cyclase, protein kinase A. Human melanogenesis regulatory proteins such as MAPK1, CREB3, and CREBP, have binary interaction with the protein of herpesvirus, hepatitis C virus, Human immunodeficiency virus type 1, Simian virus 40, and Human adenovirus A and …

Design And Synthesis Of Novel No-Drug Hybrid Compound And Green Catalytic Activity Evaluation Of Synthesized Silver Nanoparticles-Halloysite Nanocomposite, Majed Abdullah Bajaber

LSU New Orleans Theses and Dissertations

Acetaminophen is a well-known analgesic that can manage pain and reduce fever. SCP-1 is a derivative of acetaminophen that showed significantly reduced hepatotoxicity and nephrotoxicity comparative to acetaminophen. Nitric oxides have been well known to play a key role in a wide variety of physiological and pathophysiological important processes. It was therefore of interest to synthesize a nitric oxide donor linked to SCP-1 that could have enhanced analgesic and antipyretic activity. A furoxan CAS 1609 as NO-donor was synthesized and linked to SCP-1 successfully. The furoxan CAS 1609 was initially synthesized from tetronic acid to give 1,2- dioxime in 86 …

Synthesis Of Novel Thiazole And Pyrazole Derivatives As Antimicrobial And Anticancer Agents, Md Mahbub Kabir Khan

Student Theses and Dissertations

This thesis contains two chapters. In chapter one, I report the synthesis of new pyrazole derivatives from dicarboxylic acid containing phenyl-derived, monotrifluoromethyl phenyl-derived, and acetovanillone-derived pyrazole aldehydes using Hantzsch ester. All of our pyrazole compounds have been synthesized efficiently using Hantzsch ester without any catalyst. Most of our pyrazole and thiazole compounds have been effectively recrystallized with acetonitrile and methanol respectively. We have synthesized 99 different pyrazole, 17 fused-thiazole ethisterone, and D-(-) norgestrel derivatives in good yield. In the present research, it has been shown possible to synthesize novel pyrazoles and thiazoles by using readily available starting materials and benign …

Synthesis Of New Pyrazole & Thiazole Derivatives As Antimicrobial And Anticancer Agents, Ibrahim Saleh Alkhaibari

Student Theses and Dissertations

This thesis contains two chapters. In chapter one, we are reporting an efficient synthesis of eighty new pyrazole derivatives: sixty 4-trifluoromethyl and 3,5 bis(trifluoromethyl)phenyl substituted pyrazole-derived anilines, and twenty 4-trifluoromethyl-phenyl substituted pyrazole-derived hydrazones. Some of the pyrazole derivatives have been tested against several bacterial strains and have shown promising results. In Chapter two, we are reporting a synthesis of novel fused-thiazole- nootkatone derivatives. These compounds have been tested as well against a broad spectrum of Gram-positive and Gram-negative bacteria. However, they have just shown activity against some of the Gram-positive bacteria. Further anti-cancer and toxicity studies of these compounds are …

Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon

Electronic Theses and Dissertations

This thesis describes the isolation, structure elucidation, and synthesis of natural products from marine cyanobacteria. A crude extract from a cyanobacterium collected in Curacao showed selective affinity for the dopamine D₅ receptor in a screen against a panel of CNS receptors. Due to the high similarity of the D₅ and D₁ receptor, to date there are no known ligands that differentiate them. Attempts to purify the compound responsible for this affinity led to the isolation of the known compound caylobolide A. A second extract from a cyanobacterium collected in Panama underwent bioassay-guided fractionation and yielded the novel …

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.

New Alkaloids From Selected Malaysian Alstonia And Lycopodium Species And Their Biological Activity, Soon Yee Joanne Yeap

Student Works (2020-2029)

Two Malaysian plants, Alstonia penangiana Sidiyasa (family: Apocynaceae) and Lycopodium platyrhizoma J.H.Wilce (family: Lycopodiaceae), were investigated for their alkaloidal composition. This project represents the first reported phytochemical study on these two plant species. A total of 94 alkaloids (1−94) were isolated and characterized from the leaf and stem-bark extracts of Alstonia penangiana, a plant endemic to Penang Island, Malaysia. Of these, 32 are new alkaloids. The leaf extract of A. penangiana yielded a total of 15 new alkaloids, including a pair of type-A and type-B macroline isomers (1, 2), four macroline oxindoles (20–23), three talpinine-type oxindoles (41–43), two ajmaline alkaloids …

Sufex Activation With Ca(Ntf2)2: A Unified Strategy To Access Sulfamides, Sulfamates, And Sulfonamides From S(Vi) Fluorides, Nicholas Ball, Subham Mahapatra, Cristian P. Woroch, Todd W. Butler, Sabrina N. Carneiro, Sabrina C. Kwan, Samuel R. Khasnavis, Junha Gu, Jason K. Dutra, Beth C. Vetelino, Justin Bellenger, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds.

Synthesis Of The Natural Alkaloids Angustureine, Cuspareine, Galipeine, Galipinine Using Α-Aminocycloalkyl Copper Reagents, Zane Bertoli

Master of Science in Chemical Sciences Theses

Tetrahydroquinolines (THQs) are a group of N-heterocyclic molecules derived from natural sources. They show a wide range of interesting biological activity and have been the basis for a variety of different medications including antibacterial and antiparasitic drugs. The Hancock alkaloids, Galipinine, Galipeine, Cuspareine and Angustureine, are natural 1,2,3,4- tetrahydroquinoline compounds that are found in the South American Angostura tree. Extracts containing these alkaloids have been used to treat fever, dysentery and other ailments. Interestingly, These compounds have shows in vitro antimalarial activity. However, it does not appear in the literature that they have been evaluated for their potential antibiotic activity. …

Synthesis And Evaluation Of Novel Biologically Active Compounds, Madhurima Das

LSU New Orleans Theses and Dissertations

SCP-1, a potent derivative of acetaminophen, exhibits significantly diminished hepatotoxicity and nephrotoxicity relative to acetaminophen and nitrate ester derivatives of acetaminophen. It was therefore of interest to explore the development of nitric oxide donor analogs of SCP-1 to identify compounds that could have enhanced analgesic and/or antipyretic activity while taking advantage of the very low liver and kidney toxicity inherent to SCP-1. In this project, a series of nitrate ester analogues of the SCP-1 were prepared as potential nitric oxide donors. The synthesis of SCP analogs was achieved by triflic acid catalyzed O-acylation of SCP-1 with chloroalkanoyl chlorides followed by …

Silver-Catalyzed Synthesis Of Disubstituted Fluorinated Isoxazoles, Micah Stewart

Honors Theses

The presence of fluorine can provide organic compounds with useful biological properties, such as increased metabolic stability and drug uptake. Because of these advantages, fluorinated compounds make up about 30% of the drug industry. However, fluorination of complex molecules is difficult due to fluorine’s high electronegativity.

Fluorinated isoxazoles are of particular interest in the pharmaceutical industry. Isoxazoles are five-membered heterocycles with oxygen and nitrogen in the 1, 2 positions that are able to engage in interactions unavailable to other ring structures, conferring advantageous biological properties upon compounds containing them. However, there are limited synthetic routes for fluorinated isoxazoles, and those …