Chemistry Commons^™

Methodology Utilizing Triphosgene To Promote Cyclization Of Epoxy Ketones To Pyranoside Derivatives Via Proposed Epoxonium Ions, Isaac Camargo Dos Reis

LSU Master's Theses

The development of new methodologies in organic chemistry is of great importance. In fact, the discovery and creation of new reactions frequently uncovers new chemical reactivities and creates new areas of chemistry. The purpose of this thesis is to present the development of new synthetic reactions that were discovered through previous findings. Additionally, the main theme of this work relies on the intermediacy of a cationic reactive intermediate: epoxonium ions. Chapter 1 provides a brief review of bicyclic epoxonium ions and methods for their generation, as well as their utility in the synthesis of interesting heterocycles. Furthermore, Chapter 1 illustrates …

Records Of Enriched Uranium Atmospheric Deposition In Pond Sediments In Piketon, Oh, Brianna Herner, Brian Majestic, Michael Ketterer

DU Undergraduate Research Journal Archive

The enrichment of uranium, often for nuclear weapons programs and commercial nuclear reactors, produces higher concentrations of radioactive uranium 235 (²³⁵U) than what naturally occurs, which can pose a human health hazard. The most abundant naturally occurring uranium isotope is ²³⁸U, which is still radioactive, however a higher concentration of ²³⁵U skews the observed isotopic uranium distribution. The Department of Energy Portsmouth Gaseous Diffusion Plant, located near Piketon, OH, enriched uranium from 1954 to 2001 and ²³⁵U pollution has recently been detected in air and sediment samples in the surrounding community. The extent of the …

Cyclobutanone Inhibitor Of Cobalt-Functionalized Metallo-Γ-Lactonase Aiia With Cyclobutanone Ring Opening In The Active Site, Cory T. Reidl, Romila Mascarenhas, Thahani S. Habeeb Mohammad, Marlon R. Lutz Jr, Pei W. Thomas, Walter Fast, Dali Liu, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

An α-amido cyclobutanone possessing a C10 hydrocarbon tail was designed as a potential transition-state mimetic for the quorum-quenching metallo-γ-lactonase autoinducer inactivator A (AiiA) with the support of in-house modeling techniques and found to be a competitive inhibitor of dicobalt(II) AiiA with an inhibition constant of Ki = 0.007 ± 0.002 mM. The catalytic mechanism of AiiA was further explored using our product-based transition-state modeling (PBTSM) computational approach, providing substrate-intermediate models arising during enzyme turnover and further insight into substrate–enzyme interactions governing native substrate catalysis. These interactions were targeted in the docking of cyclobutanone hydrates into the active site of …

Lipoates As Building Blocks Of Macromolecules, Mojdeh Raeisi

Chemistry Theses and Dissertations

Since the discovery of Lipoic acid in the early 1950s, there have been several studies to further investigate properties and applications of this interesting, naturally occurring compound. In 1956, the dynamic nature of disulfide bonds in Lipoic acid was reported, which can exist through conversions of monomeric disulfide, polymeric disulfide, and reduced form (dithiol) from one to another under proper conditions. This dynamic nature and reducibility of disulfide bonds via thiol-disulfide exchange, opened doors to the use of Lipoic acid in drug delivery systems, especially for delivery to cancer cells that suffer from overexpression of glutathione – a thiol-bearing tripeptide …

Aerosol Vapor Synthesis Of Organic Processable Pedot Particles And Measuring Electric Conductivity Using A 3d Printed Probe Station, Yang Lu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Conducting polymers are organic semiconductors characterized by conjugated backbones (alternating single-double bonds) that enable mixed ionic-electronic conductivity. Their polymeric nature, tunable band structure and reversible redox capability have demonstrated fundamental advances in the fields ranging from electrochemical energy storage, sensing, to electro/photo catalysis and neuromorphic engineering. Conjugated backbones, the origin of all the unique physical and chemical properties associated with conducting polymers, prevent their solubility due to high lattice energy which hinders processing. Current solution utilizes a long-chain polymer (PSS) as dopants to render conducting polymer water dispersible (PEDOT:PSS). Nonetheless, PSS is highly acidic and hydrophilic limiting applicability with acid-incompatible …

Cu-Promoted C-H Bond Hydroxylation Inspired By Cu-Dependent Metalloenzymes, Rachel Trammell

Chemistry Theses and Dissertations

From 2003 to 2015, Schӧnecker and Baran proposed a dinuclear Cu/O₂ species in their mechanistic proposal for the hydroxylation of sp³ C-H bonds within their systems (proposed based on yields). Inspired from the site selectivity of this methodology and poor analysis of the mechanism, the first project was inspired to re-examine the sp³ C-H bond hydroxylation by Schrӧnecker and Baran and perform an intensive investigation into understanding how Cu/O₂ interact which led us to propose a new mechanism based on the evidence collected (i.e., LCu^II-hydroperoxide species that undergoes homolytic O-O bond cleavage). From there …

Targeted Combination Therapy Of Nsclc Using Taxol And Fingolimod Loaded Nanoceria, Raghunath Narayanam

Electronic Theses & Dissertations

Among various types of cancers, lung cancer reports highest death rate and Non-Small cell lung cancer causes highest mortality in lung cancers. This is mainly due to the scarcity of treatment options and the available treatment shows numerous adverse effects. In the recent times, nanotechnology paved a new path for the diagnosis and therapy of cancer. In this study, we worked on a novel, multifunctional nanoceria (NC) platform loaded with two unique drugs taxol and fingolimod, which acts in their own ways providing synergic therapeutic effect. We hypothesized that the usage of the polyacrylic acid (PAA) coated nanoceria (PNC) increases …

Integrated Mass Spectrometry-Based Method In Protein Chemistry: Metal-Binding Protein And Integral Membrane Protein, Chunyang Guo

Arts & Sciences Graduate Student Theses and Dissertations

Most biological processes are associated with protein catalysis. Characterizing protein structure, therefore, is crucial for understanding biological function. Mass spectrometry (MS)-based methods have emerged as a pivotal biophysical tool to interrogate protein structures; they can characterize protein-ligand/protein complexes that are refractory to conventional high-resolution means such as X-ray crystallography, Cryo-EM, and nuclear magnetic resonance (NMR) spectroscopy, in part owing to high molecular weight and significant flexibility. The integrated MS-based platform will provide topology and structural information of proteins from sketch to detail; native MS identifies protein complexes’ composition and stoichiometry; hydrogen-deuterium exchange MS (HDX-MS) detects the protein complexes’ dynamic change …

Synthesis And Characterization Of Putative Triplet Sensitizers In The Dark Pathway To Cyclobutane Pyrimidine Dimers Of Dna, Yanjing Wang

Arts & Sciences Graduate Student Theses and Dissertations

The cyclobutane pyrimidine dimer (CPD) is the major photoproduct resulting from direct absorption of UVB radiation in sunlight by DNA that results in C to T mutations found in human skin leading to skin cancer. CPDs can also be produced through the action of photosensitizers that can absorb longer wavelength UVA that is not absorbed efficiently by DNA and transfer triplet energy to the DNA. Most recently, CPDs was discovered to be formed in the dark following UV irradiation of melanocytes. This dark pathway was proposed to result from an indirect pathway to CPDs that involves triplet energy transfer from …

Metal Salt Hydrolysis For Electrochemically Active Conducting Polymer Nanocomposites, Hongmin Wang

Arts & Sciences Graduate Student Theses and Dissertations

The diversity of nanostructures obtained from organic polymerization is limited when compared to the vast amount of inorganic nanostructures. This dissertation will focus on a synergistic mechanism between organic polymerization and in situ inorganic salt hydrolysis for developing electrochemically active organic-inorganic hybrid nanostructures. The degree of polymerization, crystallinity and doping level of the conjugated polymer backbone is controlled using oxidative radical vapor-phase polymerization resulting in organic semiconductors featuring high crystallinity and superior electrical conductivity. An aqueous metal salt solution of iron (III) chloride serves as an oxidant for initiating the polymerization and interestingly, this inorganic salt hydrolyzes in situ producing …

In-Situ Imaging Of Surface Heterogeneity In Semiconductor Photocatalysts Using Singlemolecule Fluorescence Microscopy, Meikun Shen

Arts & Sciences Graduate Student Theses and Dissertations

Metal oxide semiconductors have been used as promising photocatalysts to convert solar energy into useful fuels, such as water splitting, carbon dioxide reduction, and nitrogen fixation reactions. However, the typical metal oxide photocatalysts' efficiency often suffers from their weak visible light absorption and low charge carrier mobilities. One common strategy to mitigate these limitations is to introduce oxygen vacancies into the lattice of the semiconductor photocatalysts. This strategy has been applied to many metal oxide photocatalysts, such as titanium oxide, tungsten oxide, and zinc oxide, and oxygen vacancies indeed enhance their catalytic activities. Various roles of oxygen vacancies have all …

Developing An Inquiry-Based Laboratory Project For Chem 142l Course At Bsu, Manuel Pina

Honors Program Theses and Projects

In addition to content knowledge, critical and independent thinking, scientific reasoning, and problem-solving skills are essential in preparing next generation of successful workforce. Since one of the biggest advantages of STEM disciplines is a “must-have” hands-on laboratory experience, it is intuitive to exploit this learning space to reinforce afore-mentioned skills. In this context, project-based (PBL) or inquiry-based (IBL) laboratory experiences are rapidly becoming mainstream pedagogical choice for many STEM instructors across United States.^[1-4] PBL, and IBL are learning experiences that offer students an opportunity to experience realistic scientific process of discovery through carefully designed inquiry-driven and/or open-ended investigative laboratory …

Synthesis And Crystal Structures Of 3,6-Di­Hy­Droxy­Picolinic Acid And Its Labile Inter­Mediate Dipotassium 3-Hy­Dr­Oxy-6-(Sulfonato­­Oxy)Pyridine-2-Carboxyl­Ate Monohydrate, Edward J. Behrman, Sean R. Parkin

Chemistry Faculty Publications

A simplified two-step synthesis of 3,6-di­hydroxy­picolinic acid (3-hy­droxy-6-oxo-1,6-di­hydro­pyridine-2-carb­oxy­lic acid), C₆H₅NO₄ (II), an inter­mediate in the metabolism of picolinic acid, is described. The crystal structure of II, along with that of a labile inter­mediate, dipotassium 3-hy­droxy-6-(sulfonato­oxy)pyridine-2-carboxyl­ate monohydrate, 2K⁺·C₆H₃NO₇S²⁻·H₂O (I), is also described. Compound I comprises a pyridine ring with carboxyl­ate, hydroxyl (connected by an intra­molecular O—H⋯O hydrogen bond), and sulfate groups at the 2-, 3-, and 6-positions, respectively, along with two potassium cations for charge balance and one water …

Steady-State Transmembrane Water Exchange In Proliferating Cultures Of Saccharomyces Cerevisiae, Joseph O'Malley Armstrong

Dissertations and Theses

Cellular water exchange is often considered in terms of a change in volume, where a net flux of water moves across the cell membrane due to a change in osmotic pressure. Osmotic pressure can cause a cell to shrink or swell, however, rapid water exchange persists across the membrane even when the volume of the cell is constant. Steady-state transmembrane water exchange describes the exchange of water across the cell membranes which results in no net change in cell volume. This exchange is astonishingly rapid; the entire pool of intracellular water of a Saccharomyces cerevisiae cell may exchange 2-5 times …

Effects Of Environmental Change On Ancestral Pueblo Fishing In The Middle Rio Grande, Jonathan William Dombrosky

Anthropology ETDs

It has long been assumed that fishes were unimportant in the diet of past Pueblo people in the U.S. Southwest. Yet, small numbers of fish remains are consistently recovered from Late pre-Hispanic/Early Historic archaeological sites in the Middle Rio Grande of New Mexico. The end of drought conditions may have impacted food choice and fishing decisions during this time. I use behavioral ecology to understand how fishing could have been an optimal food-getting strategy for Ancestral Pueblo farmers. Stable isotope analysis offers a way to account for environmental change. I provide a refined ¹³C Suess correction model to support …

Beyond Structural Motifs: The Frontier Of Actinide-Containing Metal–Organic Frameworks, Corey R. Martin, Gabrielle A. Leith, Natalia B. Shustova Prof. Dr.

Faculty Publications

In this perspective, we feature recent advances in the field of actinide-containing metal–organic frameworks (An-MOFs) with a main focus on their electronic, catalytic, photophysical, and sorption properties. This discussion deviates from a strictly crystallographic analysis of An-MOFs, reported in several reviews, or synthesis of novel structural motifs, and instead delves into the remarkable potential of An-MOFs for evolving the nuclear waste administration sector. Currently, the An-MOF field is dominated by thorium- and uranium-containing structures, with only a few reports on transuranic frameworks. However, some of the reported properties in the field of An-MOFs foreshadow potential implementation of these materials and …

Beyond Structural Motifs: The Frontier Of Actinide-Containing Metal–Organic Frameworks, Corey R. Martin, Gabrielle A. Leith, Natalia B. Shustova

Faculty Publications

In this perspective, we feature recent advances in the field of actinide-containing metal-organic frameworks (An-MOFs) with a main focus on their electronic, catalytic, photophysical, and sorption properties. This discussion deviates from a strictly crystallographic analysis of An-MOFs, reported in several reviews, or synthesis of novel structural motifs, and instead delves into the remarkable potential of An-MOFs for evolving the nuclear waste administration sector. Currently, the An-MOF field is dominated by thorium- and uranium-containing structures, with only a few reports on transuranic frameworks. However, some of the reported properties in the field of An-MOFs foreshadow potential implementation of these materials and …

Chemical Characterization Of Toxicologically Relevant Molecules In Cannabis Concentrates And Vaporizer Aerosols, Jiries Meehan-Atrash

Dissertations and Theses

Consumption of cannabis concentrates using the relatively novel non-combustion methods dabbing and vaping has steadily grown in popularity as cannabis legalization in North America has allowed increased access to sophisticated cannabis products and technology. In order to assess the safety of these products, it is necessary to gain a chemical understanding of the decomposition reactions that occur when the active ingredients are heated in the conditions seen when dabbing or vaping. This dissertation contains a manuscript that details efforts to structurally characterize a toxic cannabis concentrate adulterant, and three manuscripts that studied the chemical decomposition of the two primary cannabis …

Explorations Of Thermus Thermophilus Hb8 Transcription Factors Ttha1437 And Ttha1719 Using The Combinatorial Selection Method Repsa, Sarah Claire Sneed

Master of Science in Chemical Sciences Theses

In all organisms, genes exist that encode for regulatory proteins, called transcription factors (TFs) that can activate or repress transcription of specific genes depending on their biological function. Thermus thermophilus HB8 is speculated to contain 2,245 genes, of which 70 are postulated to be transcription factors. However, but for very few, little is known regarding the genes they regulate and their biological functions. The novel combinatorial method Restriction Endonuclease Protection, Selection, and Amplification (REPSA) has been successful for identifying and validating consensus binding sequences in T. thermophilus HB8 with previously studied TFs. Here REPSA was explored as a technique and …

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 …

Taipei Taiwan - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Seoul Korea - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Leicester United Kingdom

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)

Lisbon Portugal - 1994

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)

Monterrey Mexico - 1995

World Data - North America

Relevant Publications

Environmental Science & Technology Publication (1997)

Final Report

Tokyo Japan - 1995

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Malaysia - 1995

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Hong Kong - 1993

World Data - Asia

Relevant Publications

Environmental Science & Technology Publication (1995)

Melbourne - 1992

World Data - Australia

Relevant Publications

Environmental Science & Technology Publication (1995)

Final Report

Milan Italy - 1994

World Data - Europe

Relevant Publications

Environmental Science & Technology Publication (1995)