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Full-Text Articles in Chemistry

The Effect Of Variation Of N-Substituents On Oxidopyridinium Ions In (4+3) Cycloadditions, Zahria Patrick, Madison Clark Jan 2024

The Effect Of Variation Of N-Substituents On Oxidopyridinium Ions In (4+3) Cycloadditions, Zahria Patrick, Madison Clark

Undergraduate Research Symposium

The aim of this research project is to expand the scope of 4 + 3 cycloadduct chemistry by varying functional groups attached to the prerequisite oxidopyridinium ion for each respective cycloadduct product. While N-substitution of the pyridinium precursor is known to proceed smoothly if alkylated by a lone methyl group, we evaluated the effect a larger alkyl group would have on the overall yield of the 4 + 3 cycloadduct product.

Isobutyl triflate, generated from the known reaction between isobutyl alcohol and triflic anhydride, was reacted with ethyl 5-hydroxy-nicotinate to generate the respective N-isobutyl oxidopyridinium ion in quantitative …


The Roaring Lion Of Berlin: The Life, Thought, And Influence Of Eugen Dühring, Arden Roy Jan 2024

The Roaring Lion Of Berlin: The Life, Thought, And Influence Of Eugen Dühring, Arden Roy

Undergraduate Research Symposium

The life and influence of 19th-century German polymath Eugen Dühring remain but a mere footnote in the history of ideas, being primarily relegated to the status of little more than a theoretical rival to Marxism in the German socialist movement and the occasional object of Freidrich Nietzsche's rhetorical flogging. Despite the current consensus on the subject, Eugen Dühring was a scholar of vast, remarkable learnedness, contributing greatly to philosophy, economics, and the natural sciences. The aim of this talk will be to clear the fog surrounding the life and work of the controversial blind scholar and give an account of …


Etherification Of Propargylic Alcohol Using Ferrocenium Ions, Cody Amann, Sai Anvesh Bezawada, Eike B. Bauer Jan 2024

Etherification Of Propargylic Alcohol Using Ferrocenium Ions, Cody Amann, Sai Anvesh Bezawada, Eike B. Bauer

Undergraduate Research Symposium

Etherification of Propargylic Alcohol using Ferrocenium Ions

Cody Amann, Sai Anvesh Bezawada and Eike B. Bauer*

Department of Chemistry and Biochemistry, University of Missouri-St.Louis, MO 63121

Our research efforts are directed toward the improvement of iron-based catalyst systems. The Bauer research group recently found that the ferrocenium cation is a catalytically active in the etherification of propargylic alcohols. My research was to compare the effect of two different counteranions of the ferrocenium cation on the catalytic activity. Etherification test reactions were performed using 2-methyl-2-phenol-propargylic alcohol and n-butanol to afford the corresponding propargylic ether substitution products. The complexes used …


Determination Of Antibody Affinity For The Alzheimer’S Amyloid-Β Protein, Bree Carlton Jan 2024

Determination Of Antibody Affinity For The Alzheimer’S Amyloid-Β Protein, Bree Carlton

Undergraduate Research Symposium

Alzheimer's Disease (AD) is a common form of dementia that is characterized by inflammation, loss of brain mass, and loss of motor function and memory. One of the pathological hallmarks of AD is the accumulation of Amyloid-β (Aβ) in the brain as senile plaques. Aβ is formed from a large protein called Amyloid Precursor Protein (APP) when specific enzymes cut a segment of the protein into a shorter polypeptide chain, Aβ. Different aggregation species were used in this project, specifically monomers and protofibrils. Monomers are naturally occurring and nontoxic, while protofibrils are neurotoxic and neuroinflammatory. One way that Aβ can …


Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder Mar 2023

Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder

Undergraduate Research Symposium

Triple-negative breast cancer (TNBC) is one of the most aggressive and challenging breast cancer subtypes to treat, as these cancer cells lack three common receptors: estrogen, progesterone, and human epidermal growth factor receptor 2. The multiple oxidation states transition metals can occupy have made this narrowly explored group popular for anti-cancer research in recent decades. Furthermore, the success of cisplatin, which has platinum as a metal center, while being a cancer-fighting agent with serious side effects, has caused other metal centers to be investigated as possible alternatives as chemotherapeutic drugs. Copper, as a biologically essential metal, makes an attractive candidate …


The Synthesis Of Deuterated Isohumulones For Use As Internal Standards In Lc-Ms Stable Isotope Dilution Assays, Patrick Gleason, Bruce Hamper Dr. Jun 2022

The Synthesis Of Deuterated Isohumulones For Use As Internal Standards In Lc-Ms Stable Isotope Dilution Assays, Patrick Gleason, Bruce Hamper Dr.

Undergraduate Research Symposium

Humulones are compounds that are prevalent in the hops flowers (Humulus Lupulus) used in beer brewing. These compounds undergo isomerization during the brewing process, and the resulting isohumulones are considered to be the primary contributors to the bitter flavors present in beer. As such, quantifying their presence, and the relative presence of their homologs(n-, co-, ad-), is of great importance in the characterization of beer. In this effort, one of the homologs of humulone (co) was isolated before being subsequently isomerized and deuterated for the purpose of analyzing beer by stable isotope dilution assay mass spectrometry(SIDA-MS). The addition of this …


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 Mar 2022

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 …


Access To Nitrogen Heterocycles Via Borrowing Hydrogen Catalysis, Robert P. Reynolds, Kellen P. Mcguire, Conor T. Mccormick, Kyle M. Lambert Mar 2022

Access To Nitrogen Heterocycles Via Borrowing Hydrogen Catalysis, Robert P. Reynolds, Kellen P. Mcguire, Conor T. Mccormick, Kyle M. Lambert

Undergraduate Research Symposium

Nitrogen heterocycles are ubiquitous motifs which occur as the core structure of several alkaloid natural products exhibiting inherent biological activity against an array of bacteria, fungi, viruses, and cancer cell lines. These azacycles serve as key synthetic building blocks for medicinal chemists to access more structurally complex and diverse compounds with tunable biological properties. A synthetic approach to these valuable motifs employing intramolecular borrowing hydrogen catalysis has been developed. The utility of the developed chemistry will be applied to synthetic efforts towards the recently isolated Cylicomorphins A-E.


Spectral Analysis Of A New Electronic Transition Of Platinum Fluoride, Ptf, Carol Welch Sep 2021

Spectral Analysis Of A New Electronic Transition Of Platinum Fluoride, Ptf, Carol Welch

Undergraduate Research Symposium

The electronic landscape of platinum containing molecules has been the focus of numerous spectroscopic studies in recent years, because of the difficulty in describing electronic structure theoretically due to electronic correlations and relativistic effects. A collective effort by spectroscopitsts and theoreticians to investigate the diatomic molecule platinum fluoride, PtF, has included research such as developing potential energy diagrams and performing analyses on rotational transitions with microwave spectroscopy. One group observed electronic transitions of PtF using laser vaporization/reaction with jet free expansion and laser induced spectroscopy. A highly effective method for observing and analyzing electronic transitions of small, metal-containing molecules like …


Building Blocks For Oligosaccharide Synthesis, Mariya Novakova, Mithila Bandara, Catherine Alex Apr 2019

Building Blocks For Oligosaccharide Synthesis, Mariya Novakova, Mithila Bandara, Catherine Alex

Undergraduate Research Symposium

Carbohydrates (sugars or glycans) are involved in many processes and are referred to as the “essential molecules of life.” Our life begins with fertilization, which takes place via carbohydrate-protein recognition. Our journey with sugars continues with human milk that becomes the ideal first food for babies. Oligosaccharides present in human milk (HMOs) can provide prebiotic effects, function as antimicrobial agents, and provide necessary nutrients for the development of the brain and cognition of infants. Throughout our lifetime, sugars are involved in many upkeeping processes and defensive mechanisms including joint lubrication, cell growth, antigenic determination, anti-inflammation, immune response. Presented herein is …


Molecular Assembly Line For Intramolecular Electron Transferring Bimetallic Fe And Mn Cyanometallate Clusters, Austin L. Stelling, Nigam Rath Apr 2019

Molecular Assembly Line For Intramolecular Electron Transferring Bimetallic Fe And Mn Cyanometallate Clusters, Austin L. Stelling, Nigam Rath

Undergraduate Research Symposium

There has been emerging worldwide research dedicated to finding molecular complexes suitable for molecule-based high-density information storage via intramolecular electron transfer. A known cyanoferrate switchable material, Prussian Blue, has inspired research efforts of Holmes et al. to create families of heterometallic Prussian Blue derivatives that display optical and magnetic behavioral transitions with the variation of light and temperature. The task for my undergraduate research project is synthesizing massive switchable molecular clusters containing cyano-bridged Fe and Mn units. During the process, Marcus-Hush theory of electron transfer was an important consideration during the synthesis of tri- and tetranuclear complexes with varying redox …


Comparison Of Hop Derived Humulone Constituents In Beer Using Uv-Vis, Hplc, And Lc-Ms, Aaron I. Boland, Nicholas Viriyasiri, Lorna Espinosa, Hunter Campbell, Kurt Driesner Apr 2019

Comparison Of Hop Derived Humulone Constituents In Beer Using Uv-Vis, Hplc, And Lc-Ms, Aaron I. Boland, Nicholas Viriyasiri, Lorna Espinosa, Hunter Campbell, Kurt Driesner

Undergraduate Research Symposium

Lupulones and humulones are two families of compounds derived from the hop flower (Humulus lupulus), utilized in brewing beer. Isohumulones are produced during the boiling process by isomerization reactions of humulones and are the primary bittering compounds in beer. The concentration in parts per million (ppm) of isohumulone is reported as IBU (International Bittering Units). Measurement of these compounds is valuable to brewers, but is confounded by other constituents in beer which may also absorb at the 275nm wavelength in UV-Vis spectrometry, the industry standard method. 25 samples were measured using UV-Vis, then analyzed by High Precision Liquid Chromatography (HPLC) …


Hplc-Based Automated Synthesis: Building Blocks For The Development Of New Technologies, Hayley B. Steber, Matteo Panza Apr 2019

Hplc-Based Automated Synthesis: Building Blocks For The Development Of New Technologies, Hayley B. Steber, Matteo Panza

Undergraduate Research Symposium

Use of automated technologies is of increasing interest in glycosciences.1 Among the new methodologies, a number of recent advancements have emerged in the area of solid-phase oligosaccharide synthesis.2-3 Demchenko and Stine developed a synthesizer based on a commercial HPLC instrument that was recently improved by the implementation of the autosampler for the delivery of glycosylation promoters.4 Despite the added versatility, the system still lacks complete automation. The foundations of glycan syntheses are acceptors and donors, grouped together under the general term of building blocks. Presented herein is the synthesis of the building blocks of the rhamno and galacto series. We …


Comparison Of Hop Derived Humulone Constituents In Beer Using Uv-Vis, Hplc, And Lc-Ms, Aaron Boland, Nicholas Viriyasiri, Hunter Campbell Apr 2019

Comparison Of Hop Derived Humulone Constituents In Beer Using Uv-Vis, Hplc, And Lc-Ms, Aaron Boland, Nicholas Viriyasiri, Hunter Campbell

Undergraduate Research Symposium

Lupulones and humulones are two families of compounds derived from the hop flower (Humulus lupulus), utilized in brewing beer. Isohumulones are produced during the boiling process by isomerization reactions of humulones and are the primary bittering compounds in beer. The concentration in parts per million (ppm) of isohumulone is reported as IBU (International Bittering Units). Measurement of these compounds is valuable to brewers, but is confounded by other constituents in beer which may also absorb at the 275nm wavelength in UV-Vis spectrometry, the industry standard method. 25 samples were measured using UV-Vis, then analyzed by High Precision Liquid Chromatography (HPLC) …


Toward Unraveling The Mechanisms Of “Green” Mechanochemical Reactions, Richard Chen, Mehmet Kerem Gokus Feb 2019

Toward Unraveling The Mechanisms Of “Green” Mechanochemical Reactions, Richard Chen, Mehmet Kerem Gokus

Undergraduate Research Symposium

The mechanical processing of solids, such as milling or grinding powders, often leads to mechanochemical reactions. Mechanochemistry affords “green” synthetic routes avoiding or reducing the use of solvents, thus providing environmentally friendly and cost-effective synthetic alternatives for many materials. The solid-state reactants are usually ground together with small quantities of organic solvents, called “liquid assisted grinding” (LAG). LAG increases the reaction rates, it can yield products from otherwise unreactive mixtures, it increases the products crystallinity, and it selectively leads to crystal structures (polymorphs) of the products, depending on the quantities and physicochemical properties of the liquids used in LAG.

Mechanochemistry …