Other Chemistry Commons^™

Products Of An Acid-Catalyzed 1-Methylcyclopentene Reaction, Erin Burke

Campus Research Month

The poster presents research on the alternate products produced from 1-methylcyclopentene across different concentrations of sulfuric acid catalyst.

Effective Microwave-Assisted Approach To 1,2,3-Triazolobenzodiazepinones Via Tandem Ugi Reaction/Catalyst-Free Intramolecular Azide–Alkyne Cycloaddition, Maryna O. Mazur, Oleksii S. Zhelavskyi, Eugene M. Zviagin, Svitlana V. Shishkina, Vladimir I. Musatov, Maksim A. Kolosov, Elena H. Shvets, Anna Yu. Andryushchenko, Valentyn A. Chebanov

Department of Chemistry: Faculty Publications

A novel catalyst-free synthetic approach to 1,2,3-triazolobenzodiazepinones has been developed and optimized. The Ugi reaction of 2-azidobenzaldehyde, various amines, isocyanides, and acids followed by microwave-assisted intramolecular azide–alkyne cycloaddition (IAAC) gave a series of target heterocyclic compounds in moderate to excellent yields. Surprisingly, the normally required ruthenium-based catalysts were found to not affect the IAAC, only making isolation of the target compounds harder while the microwave-assisted catalyst-free conditions were effective for both terminal and non-terminal alkynes

Cown Sustains Nitrogenase Turnover In The Presence Of The Inhibitor Carbon Monoxide, Michael S. Medina, Kevin O. Bretzing, Richard A. Aviles, Kiersten M. Chong, Alejandro Espinoza, Chloe Nicole G. Garcia, Benjamin B. Katz, Ruchita N. Kharwa, Andrea Hernandez, Justin L. Lee, Terrence M. Lee, Christine Lo Verde, Max W. Strul, Emily Y. Wong, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nitrogenase is the only enzyme capable of catalyzing nitrogen fixation, the reduction of dinitrogen gas (N₂) to ammonia (NH₃). Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Nitrogen-fixing bacteria rely on the protein CowN to grow in the presence of CO. However, the mechanism by which CowN operates is unknown. Here, we present the biochemical characterization of CowN and examine how CowN protects nitrogenase from CO. We determine that CowN interacts directly with nitrogenase and that CowN protection observes hyperbolic kinetics with respect to CowN concentration. At a CO concentration of 0.001 atm, …

Sulfur Anions: Comments Upon Structure, Charles A. Kingsbury

Department of Chemistry: Faculty Publications

This work emphasizes the need for solvent simulation as well as a counterion in calculations concerning anions, although optimization may be difficult. Solvent and counterion both play a large role in conformation of the ion. Part of the reason for the success of sulfur anions in chemical reactions may be the ability of sulfone oxygen(s) to coordinate with the counterion (usually lithium). The “solvent” partially dissociates lithium from the carbanion center.

Identifying Receptors For Neuropeptides And Peptide Hormones: Challenges And Recent Progress, Md Shadman Ridwan Abid, Somayeh Mousavi, James W. Checco

Department of Chemistry: Faculty Publications

Intercellular signaling events mediated by neuropeptides and peptide hormones represent important targets for both basic science and drug discovery. For many bioactive peptides, the protein receptors that transmit information across the receiving cell membrane are not known, severely limiting these signaling pathways as potential therapeutic targets. Identifying the receptor(s) for a given peptide of interest is complicated by several factors. Most notably, cell-cell signaling peptides are generated through dynamic biosynthetic pathways, can act on many different families of receptor proteins, and can participate in complex ligand-receptor interactions that extend beyond a simple one-to-one archetype. Here, we discuss recent methodological advances …

The Mechanism Of Β-N-Methylamino-L-Alanine Inhibition Of Trna Aminoacylation And Its Impact On Misincorporation, Nien-Ching Han, Tammy J. Bullwinkle, Kaeli F. Loeb, Kym F. Faull, Kyle Mohler, Jesse Rinehart, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

β-N-methylamino-l-alanine (BMAA) is a nonproteinogenic amino acid that has been associated with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD). BMAA has been found in human protein extracts; however, the mechanism by which it enters the proteome is still unclear. It has been suggested that BMAA is misincorporated at serine codons during protein synthesis, but direct evidence of its cotranslational incorporation is currently lacking. Here, using LC-MS–purified BMAA and several biochemical assays, we sought to determine whether any aminoacyl-tRNA synthetase (aaRS) utilizes BMAA as a substrate for aminoacylation. Despite BMAA's previously predicted misincorporation at serine …

Photoassisted Synthesis Of Complex Polyheterocycles Via Rational Design Of Tailored Photoprecursors, Tina Alanna Holt

Electronic Theses and Dissertations

Natural products remain the most common source for drug leads, although diversity-oriented synthesis of unnatural complex molecules is gaining momentum. Our lab has been developing experimentally simple and straightforward approaches to complex molecular architectures via photochemical reactions involving a minimal number of experimental steps. In order to achieve this, photoprecursors were assembled via high yielding reactions. Next, we deployed photoinduced cycloadditions to create complex 3-dimentional structures. Lastly, with this obtained primary photoproduct, post-photochemical transformations were used to further grow its scaffold complexity.

One method to increase scaffold complexity is the [4+2] intramolecular cycloadditions of azaxylylenes, which are developed through standard …

Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown

Electronic Theses and Dissertations

Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …

Polyesters With Main And Side Chain Phosphoesters As Structural Motives For Biocompatible Electrospun Fibres, André E. Polloni, Viviane Chiaradia, Ronaldo José F.C. Do Amaral, Cathal Kearney, Brian Gorey, Débora De Oliveira, José V. De Oliveira, Pedro H.H. De Araújo, Claudia Sayer, Andreas Heise

Articles

Phosphoester containing polymers are promising materials in biomedical applications due to their biocompatibility and biodegradability. Utilising thiol-ene chemistry, the synthesis of two novel structural polymer motives combining polyesters and phophoester groups was explored. The first polymer was obtained by coupling ene-functional poly(thioether-phosphoester) with thiol functional poly(pentadecalactone). While the coupling reaction was successful, yields remained low presumably due to inadequate endgroup stoichiometry. The second polymer comprised phosphoester side groups conjugated to unsaturated poly(globalide). Double bond conversions up to 84% were achieved depending of the type of phosphoester thiol and relative reactant ratios. The resulting polymers transitioned from solid semicrystaline to liquid …

Structure Formation And Coupling Reactions Of Hexaphenylbenzene And Its Brominated Analog, Jacob D Teeter, Paulo S. Costa, Christoph Dobner, Mamun Sarker, Alexander Sinitskii, Axel Enders

Department of Chemistry: Faculty Publications

The on-surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C₄₂Br₂H₂₆, TPTP), and its non-brominated analog hexaphenylbenzene (C₄₂H₃₀, HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non-covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer’s structure could be achieved by moderate annealing, which is likely driven by π-bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that …

Elucidating The Interfacial Interactions Between Biomacromolecules And Functionalized Pamam-Based Materials For Biomedical Applications, Briana L. Simms

Electronic Theses and Dissertations

Polyamidoamine (PAMAM) is a dendrimer structure with a polypeptide backbone architecture. It has been utilized in a wide variety of applications but has found significant utility in biomedical applications. PAMAM has been studied extensively due to its globular structure that is similar to proteins found in the body. The branched architecture and overall size provide a favorable environment for host-guest interactions and allows for the loading of small molecules for therapeutic delivery. Although PAMAM has many benefits for use in the area of therapeutic delivery, a primary area of concern for this molecular architecture is the terminal amines that serve …

Carbon Dioxide And Particulate Matter Concentration On Hampton Roads Air Quality, Gregory Hubbard

OUR Journal: ODU Undergraduate Research Journal

Hampton Roads has been a maritime crossroads for the last 400 years. Industrialization has impacted the coastal region for the last 250 years. The expansion of the Port of Virginia in 2019 has created dense traffic in the region resulting in impacts to air quality. Two waste products that affect humans are particulate matter and carbon dioxide. Both respective emissions can cause adverse effects on humans, such as asthma, some lung cancers, and other respiratory distress. Scientists and health practitioners are studying the effects of particulate matter on human health. Hampton Roads, in particular, because of its unique location on …

Transcriptional Repressor Protein Based Macrolide Biosensor Development With Improved Sensitivity, Jayani A. Christopher

Graduate Research Posters

Macrolide antibiotics are in high demand for clinical applications. Macrolides are biosynthesized via giant assembly line polyketide synthases (PKS) which are arranged in a modular fashion. Combinatorial biosynthetic methods have been used to produce diversified macrolides by reprograming these modules and modifying tailoring enzymes required for post synthetic modifications. However it is challenging due to the size and complexity of PKSs. To overcome this challenge, new enzymes for macrolide diversification could be obtained by directed evolution where a large number of enzyme variants need to be screened. Therefore it is important to develop high throughput screening methods to identify the …

Information Architecture For A Chemical Modeling Knowledge Graph, Adam R. Luxon

Theses and Dissertations

Machine learning models for chemical property predictions are high dimension design challenges spanning multiple disciplines. Free and open-source software libraries have streamlined the model implementation process, but the design complexity remains. In order better navigate and understand the machine learning design space, model information needs to be organized and contextualized. In this work, instances of chemical property models and their associated parameters were stored in a Neo4j property graph database. Machine learning model instances were created with permutations of dataset, learning algorithm, molecular featurization, data scaling, data splitting, hyperparameters, and hyperparameter optimization techniques. The resulting graph contains over 83,000 nodes …

A Determination Of The Aerosolization Efficiency Of Drugs Of Abuse In A Eutectic Mixture With Nicotine In Electronic Cigarettes, Laerissa Reveil

Master of Science in Forensic Science Directed Research Projects

Electronic cigarettes (e-cigarettes) were originally advertised as an alternative nicotine delivery system to facilitate smoking cessation. However, their popularity for recreational use has increased due to focuses on their trendiness, convenience, and discreteness along with concerns for its use to consume drugs other than nicotine (DOTN). With the adulteration of e-liquids, usually containing nicotine, with other substances, a greater understanding on how DOTN interact with the e-liquid constituents and how they are delivered to the user is necessary. E-liquids were prepared with 50:50 propylene glycol:vegetable glycerin, pure nicotine, pure methadone hydrochloride, and 1:1 methadone hydrochloride:nicotine and aerosolized via an automated …

Characterizing The Presence Of Edta In Blood Samples, Alexandra Wright

Master of Science in Forensic Science Directed Research Projects

Blood is often a type of evidence found at crime scenes. There has been a long history of criminal cases involving blood evidence samples that were allegedly planted at the scene by a third party. Ethylenediaminetetraacetic acid, or EDTA, is an anticoagulant that is not naturally occurring in blood samples; it chelates to ions in blood to prevent clotting. If present in a blood evidence sample, it could be indicative that the blood sample may have been planted at the crime scene to implicate a suspect. EDTA is also reported to modify clothing and exist in detergents, to allow dyes …

Detection Of 2,4,6-Trinitrotoluene Using A Colorimetric Gold Nanoparticle Air Cassette Filter, Andrea I. Ferrer Vega

Master of Science in Forensic Science Directed Research Projects

Trinitrotoluene (TNT) is an explosive commonly used during military and terrorist activities. Current methods to identify this compound require sampling, transport and analysis at a forensic lab using analytical instrumentation. However, on-site detection is needed to assist efforts to prevent detonation. Gold nanoparticles have been used as sensors throughout the years due to their versatility and surface enhanced Raman scattering properties in the presence of an analyte and low limits of detection. By taking advantage of the Meisenheimer complex that TNT forms in the presence of amines, it is possible to determine its presence at picogram levels. Subsequently, adhering amine …

The Role Of Ammonia In Atmospheric New Particle Formation And Implications For Cloud Condensation Nuclei, Arshad Arjunan Nair

Legacy Theses & Dissertations (2009 - 2024)

Atmospheric ammonia has received recent attention due to (a) its increasing trend across various regions of the globe; (b) the associated direct and indirect (through PM2.5) effects on human health, the ecosystem, and climate; and (c) recent evidence of its role in significantly enhancing atmospheric new particle formation (NPF or nucleation) rates. The mechanisms behind nucleation in the atmosphere are not fully understood, although over the last decade there have been significant developments in our understanding. This dissertation aims at improving our understanding of atmospheric ammonia in the atmosphere, its spatiotemporal variability, its role in atmospheric new particle formation, and …

Physical Characteristics And Microphysical Processing Of Atmospheric Aerosol In Rural And Urban New York State, Joseph Marto

Legacy Theses & Dissertations (2009 - 2024)

Atmospheric aerosol has profound impacts on air quality, though particles of differing sizes can have profoundly different characteristics which are understated when measurements are reported as a single parameter (typically number concentration or total mass). To address some of these concerns and to better understand the nature of atmospheric aerosol, continuous particle size distributions have been measured at two sites in New York State. Measurement was performed for particle diameters between 7.6nm - 20µm at Pinnacle State Park (Addison, New York; March 2017-April 2018) and Queens College (May 2018-September 2019) at a 5-minute time resolution. At Pinnacle State Park, aerosol …

Enhanced Electrochemical And Light-Driven Co2 Reduction By Incoporating Pendant Functionality In The Second-Coordination Sphere Of Molecular Catalysts, Sayontani Sinha Roy

Electronic Theses and Dissertations

With the increase in global population and rapid industrialization, a gigantic amount of greenhouse gases is being released into the atmosphere each year. The catastrophic effect of these accumulated greenhouse gases is driving global climate change and adversely impacting our ecosystem. Popularizing the traditional renewable energy sources (such as solar and wind energy) can mitigate the problem by cutting down anthropogenic CO2 emissions, which is the major contributor to this global problem. However, the intermittent nature of these energy sources is problematic to reliably power society throughout the year. Therefore, converting CO2 to various value-added chemicals with the aid of …