Chemistry Commons^™

Bacterial-Mediated Photocatalytic Organic Oxidation, Peter J. Pellegrinelli

Theses and Dissertations

Bacteria, though well-known and widespread in scientific application, have plenty more opportunity to grow in the field of organic synthesis. The primary objective of this project was to apply the use of bioluminescent bacteria in an organic photoredox reaction intending to use the bacteria as a renewable source of light. This sustainable method, as opposed to high wattage bulbs, paves a green pathway for organic photocatalytic reactions. Using bioluminescent E. coli, the focus was on performing organic oxidation reactions with a recyclable photocatalyst. When using bacteria in conjunction with chemicals like nitromethane, it was an obstacle to keep the E. …

Synthetic, Catalytic, And Mechanistic Studies Of Supermesityl Phosphiranes And Phosphines, Ryan M. Tipker

Dartmouth College Ph.D Dissertations

Methylation of P-stereogenic phosphiranes Mes*PCH2CH(R) (Mes* = 2,4,6-(t-Bu)3C6H2, R = Me, Ph) with MeOTf gave P-stereogenic phosphiranium cations; [Mes*P(Me)CH2CH(Ph)][OTf] underwent syn-anti isomerization via P-epimerization. Mechanistic studies suggested ring opening gave a hyperconjugation-stabilized carbocation in which pyramidal inversion at P was promoted by s-interaction with the pendant cation. Attempted phosphirane protonation with HOTf resulted in ring opening and C-H activation of an o-t-Bu group to give phospholanium cations. Treatment of [Mes*P(Me)CH2CH(Ph)][OTf] with LiPPh2 gave bis(phosphino)ethanes. Copper- catalyzed P-alkylation of the secondary phosphine PHPh(Mes*) with benzyl bromides gave P-stereogenic tertiary phosphines with a supermesityl substituent.

Inhibiting Nitroso Related Methylation Of Guanine Using Dietary Supplements And Flavonoids, Elijah Gocotano, Hannah Klose

Liberty University Research Week

Undergraduate

Basic

Synthesis And Evaluation Of Biologically Active Phosphorous Heterocycles And Lipid A Antagonist Compounds, Saroj Kafle

Dissertations

Cyclophostin and cyclipostins are naturally occurring organophosphates with common structural core units and different phosphate ester substituents. Cyclophostin is a cyclic phosphate triester with a chiral center at phosphorous and C-3a carbon atom while the cyclipostins have characteristic alkyl substituents with varying chain lengths at the phosphate center. Long-chain substituted monocyclic phosphate (2b) and phosphonate (2a) analogs of cyclophostin and cyclipostin are promising inhibitors against serine hydrolases acetylcholinesterase with an IC₅₀ in the nanomolar range.

Biologically active β-lactones and lactams owe their activity, in part, to ring strain. The ring opening of β-lactones and lactams …

Additivity Of Diene Substituent Gibbs Free Energy Contributions For Diels–Alder Reactions Between Me2c=Cme2 And Substituted Cyclopentadienes, Thomas M. Gilbert, Austin S. Flemming, Brendan C. Dutmer

Faculty Articles, Papers, and Other Scholarship

Systematic computational studies of pericyclic Diels–Alder reactions between (H3C)2C═C(CH3)2, 1, and all permutations of substituted cyclopentadienes c-C5R1R2R3R4R5aR5b (R = H, CH3, CF3, F) allowed isolation of substitutional effects on Gibbs free energy barrier heights and reaction Gibbs free energies. “Average Substitution Gibbs Free Energy Correction” ΔGASC#‡/ΔGASC# values for each substituent in each position appeared to be additive. Substituent effects on barriers showed interesting contrasts. Methyl substitution at positions 5a and 5b increased barriers significantly, while substitution at all other positions had essentially no impact. In contrast, fluoro substitution at positions 5a and 5b lowered barriers more than substitution at other …

Synthesis And Properties Of Bio-Based 3d Printable Resins, Cameron Woods, Seth Taylor, Jeremiah Coughlon, Turner Perdue, Sourav Chatterjee, Jason E. Bara

Scholars Week

A photopolymer resin is a monomer that, when introduced to light of a certain wavelength, starts to polymerize into a solid. This has become a growing part of the 3D printing industry. There have been many advancements in the field of 3D printing, however, a lot of these resins are not environmentally friendly and even harmful if not handled in the correct manner. Plant based resins are becoming more and more popular because of their biodegradability and for the possibility of using renewable resources. Glycerol is a plant-based compound that is produced in excess in industry. Glycerol obtained from bioethanol …

Physiochemical Properties Of Urethane-Containing Ionic Liquids And Ionenes From A Non-Isocyanate Synthetic Approach, George Timmermann

Scholars Week

Ionic polymers that are designed to contain ionic liquids (ILs) in their backbones have been shown to exhibit a high degree of variability through changing the type of ionic character and the location of the ionic region within the molecule. This large amount of variability in both the structure and characteristics of ILs allows researchers to design task-specific ionic polymers and ILs for a variety of applications including gas separation membranes and solid polymer electrolytes. The synthesis of a specific class of ILs and ionenes through the incorporation of urethane groups with imidazolium rings by reacting carbonyl diimidazole with various …

Microscale Chemical Manipulation And Imaging Using Photoactive Molecules And Light, Uroob Haris

Chemistry Theses and Dissertations

Chemical manipulation with light has been an active and growing area of research with important implications in materials science, biotechnology, and environmental science. From early investigations of light sensitive materials for photography in the 19^th century, to printing billions of transistors on a semiconductor chip in present day, scientists have gained a deep understanding of photochemistry and the processes that allow us to harness light for everyday applications. In this work, we explore microscale fabrication and molecular imaging using light and photoactive molecules as foundational tools. We develop a visible-light mediated technique for high resolution microscale chemical lithography comprising …

Dipole Cooperativity And Polarization Frustration Determine The Secondary Structure Distribution Of Short Alanine Peptides In Water, Ying Yuan, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

The physical driving forces for secondary structure preferences of hydrated alanine peptide are investigated with B3LYP-D3(BJ) and the adaptive force matching (AFM) method. The AFM fit to the DFT surface, ALA2022, provides excellent agreement with the nuclear magnetic resonance scalar coupling constants from experiments. In turn, the model is used to gain insight into the physical driving forces behind secondary structure preferences of hydrated peptides. DFT calculations with and without the Conductor-like Screening Model (COSMO) show that the α helix is stabilized by solvent polarization due to dipole cooperativity. The two adjacent amide groups in β strand form a near-planar …

Rage Inhibitors In Neurodegenerative Diseases, V. Prakash Reddy, Puspa Aryal, Pallavi Soni

Chemistry Faculty Research & Creative Works

Nonenzymatic Reactions of Reducing Sugars with Primary Amino Groups of Amino Acids, Proteins, and Nucleic Acids, Followed by Oxidative Degradations Would Lead to the Formation of Advanced Glycation Endproducts (AGEs). the AGEs Exert Multifactorial Effects on Cell Damage Leading to the Onset of Neurological Disorders. the Interaction of AGEs with the Receptors for Advanced Glycation Endproducts (RAGE) Contribute to the Activation of Intracellular Signaling and the Expression of the Pro-Inflammatory Transcription Factors and Various Inflammatory Cytokines. This Inflammatory Signaling Cascade is Associated with Various Neurological Diseases, Including Alzheimer's Disease (AD), Secondary Effects of Traumatic Brain Injury (TBI), Amyotrophic Lateral Sclerosis …

Hydrothermal Liquefaction Of Saccharina Latissima For The Production Of Biofuel, Mayokun A. Oke

Mechanical Engineering Theses

We performed hydrothermal liquefaction of brown macroalga (Saccharina latissima) in the presence of homogenous and heterogenous catalysts such as KOH, Na₂CO₃, Pd/C, HZSM-5, Ce/HZSM-5, and Ni/SiO₂-Al₂O₃ in hot compressed water, to investigate their effects on product yield and composition in the biocrude. To investigate hydrocarbon production, we used methanol as co-solvent (methanol-to-water 1/4 vol.%) and as the only liquefaction solvent. We carried out the experiments in a batch reactor at 330^oC and 120-130 bar, and varying temperature, algae-to-water ratio, residence time, and pretreatment method. The biocrude yields …

Simulating A Flexible Water Model As Rigid: Best Practices And Lessons Learned, Raymond Weldon, Feng Wang

Chemistry & Biochemistry Faculty Publications and Presentations

Two ways to create rigid versions of flexible models are explored. The rigid model can assume the Model’s Geometry (MG) as if the molecule is not interacting with any other molecules or the ensemble averaged geometry (EG) under a particular thermodynamic condition. Although the MG model is more straightforward to create, it leads to relatively poor performance. The EG model behaves similarly to the corresponding flexible model (the FL model) and, in some cases, agrees even better with experiments. While the difference between the EG and the FL models is mostly a result of flexibility, the MG and EG models …

Synthesis And Characterization Of Some Disubstituted Cyclopentadienyl Rhenium Complexes As Potential Candidates In Semiconductive Materials, Chloe Vernon

Senior Honors Theses

Since 2000, when the Nobel Prize in Chemistry as awarded for conductive polymer research few studies have been performed concerning the conductive capabilities of discrete organometallic compounds. For this project, organometallic compounds were formed specifically with a transition metal included in the structure. Through oxidation and reduction reactions, the variation in the electrical conductivity could allow for an analysis of whether this unique structure would allow for tunability. The goal of this research was to begin with aromatic substituted fulvenes and perform various multistep synthesis processes, utilizing thallium salt intermediates, to produce several disubstituted cyclopentadienyl rhenium complexes. In this project, …

Pc-01 Synthesis Of Zinc Glycoconjugated Phthalocyanines As A Potential Phototherapeutic, Jessica A. Silva-Conejo, Katrina Mccarter, Tessa Greene, Joshua V. Ruppel

SC Upstate Research Symposium

Photodynamic Therapy (PDT) uses photosensitizers that are activated by light to produce singlet oxygen that can cause cell damage and potential cell death. Phthalocyanines are promising photosensitizers due to their absorption at clinically relevant wavelengths, meaning that they absorb at a wavelength that can penetrate deeper into tissues.

One challenge with using Phthalocyanines is that they have very low solubility in biological media. One potential approach to increase solubility is through glycoconjugation. Glycoconjugation can also be used as a strategy to increase selectivity toward targeted tissues. Glycoconjugated phthalocyanines can be synthesized using a copper catalyzed azide-alkyne cycloaddition reaction, otherwise known …

Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji

Hadhramout University Journal of Natural & Applied Sciences

In this research, two new azo dyes, 9-(2-Hydroxy-ethoxymethyl)-2-(2-hydroxy5nitrophenylazo)-1,9-dihydro-purin-6-one and 4-(2-Hydroxy-napHthalen-1-ylazo)-N-(5-methyl-isoxazol-3-yl)-benzenesulfonamide, derived from Acyclovir and Sulfamethoxazole was synthesized. The first dye synthesis was started by diazation of acyclovir, then combined with 4-nitrophenol activated with potassium hydroxide 10%, yielding 80%, and its purity was verified by thin layer chromatography (TLC). The second dye synthesis was started by diazation of Sulfamethoxazole then combined with β-naphthol activated with potassium hydroxide 10%, yielding 87%, and its purity was verified by thin layer chromatography (TLC). The identity of the resulting pigments was determined based on spectroscopic methods such as infrared spectroscopy, proton nuclear magnetic resonance spectrum …

Studies On Bonding, Syntheses, And Applications Of Diarylhalonium Compounds, Shubhendu Karandikar

Dissertations and Theses

Organic compounds containing functionalized benzenoid rings have found tremendous applications in pharmaceuticals, agrochemicals, commodity chemicals, and beyond. As a result, development of methods for the synthesis of functionalized benzenoid rings has gained much attention from the synthetic community. Although many transition-metal mediated methods to functionalize benzenoid rings are known, there has been an upsurge of activity in developing protocols for decoration of benzenoid cores promoted by p-block elements. This excitement stems from the sustainability of earth-abundant elements and unique reactivity patterns observed within the p-block. Among these, transformations promoted by hypervalent halogen compounds, and especially, the diarylhalonium salts are very …

Pyrrolopyrrole-Based Materials For High-Contrast Electrochromics, Allison Marie Hawks

Master of Science in Chemical Sciences Theses

Understanding structure-property relationships of underutilized p-conjugated chromophores is an important task for the continued discovery of materials that will find utility in organic electronic applications. Dihydropyrrolo[3,2-b]pyrroles (DHPPs) are synthetically simple and highly tailorable chromophores that can be decorated with diverse functionalities that readily manipulate optoelectronic properties useful for a variety of applications. However, a thorough understanding of how these functionalities influence properties of DHPPs that will be useful in applications such as electrochromism is unknown. Motivated to exploit the synthetic simplicity and tailorability of DHPPs, a family of DHPP chromophores was synthesized to probe how functionality and connectivity …

Diazirines And Oxaziridines As Nitrogen Transfer Reagents In Drug Discovery, Khalilia C. Tillett

USF Tampa Graduate Theses and Dissertations

Synthetic organic chemistry has long served as a driver of innovation in the drug discovery and development process. Given the prevalence of the nitrogen atom in small molecule drugs, improved methods for C–N bond installation are in high demand. Heteroatom transfer reagents such as oxaziridines and diazirines can be used to selectively deliver nitrogen atom(s) to organic compounds. Herein, I’ll describe my work utilizing Armstrong’s oxaziridine (TBDOT) in peptide backbone modification, and diazirines (TPD) in the development of a hydroamination reaction.

Peptide backbone N-amination has emerged as an attractive peptidomimetic strategy in the design of amyloid aggregation inhibitors. In addition …

Design And Fabrication Of Single-Chain Nanoparticles, Vitrimers, Bottlebrush And Comb Polymers, Logan Dugas

Dissertations

The introduction of novel dynamic exchange chemistries into polymer chains and networks has shown great potential of giving next generation polymeric materials. Within the scope of this thesis, dynamic chemistry is employed to realize single-chain nanoparticles, vitrimer networks, bottlebrush and comb polymers. CHAPTER I provides a broad introduction to the topics at hand, focusing upon the techniques utilized to achieve such materials with relevant literature and understanding of the techniques and architectures explored. CHAPTER II focuses upon the synthesis of single-chain nanoparticles via a copolymerization of polyisobutylene macromonomers with norbornene monomers equipped with pendant anthracene moieties. Through this work, the …

The Synthesis, Characterization, And Utilization Of Functionally Diverse Romp-Based Bottlebrushes, Cheyenne Liu

Dissertations

Bottlebrush polymers have garnered interest in many disciplines for their unique structure-property characteristics and potential applications. These polymers typically exhibit extended rodlike conformations as a result of sterically crowded side-chains. Further, extensive work has focused on expanding the synthetic toolbox for these systems, resulting in excellent molecular weight control, diverse functional group utility and corresponding stimuli-responsive behaviors. This dissertation examines both synthetic and stimuli-responsive tools in the context of bottlebrush systems.

A broad overview of bottlebrush characteristics, synthesis, and applications is discussed in CHAPTER I. CHAPTER II focuses on the use of a chain-transfer agent in the ring-opening metathesis polymerization …

Development Of An Lcms Method To Detect And Quantify Curcumin In A Novel Oral Formulation Of Turmeric, Brandon Renninger

Annual Research Symposium

No abstract provided.

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 …