Digital Commons Network^™

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Synthesis Of 12-Membered Tetra-Aza Macrocyclic Pyridinophanes Bearing Electron-Withdrawing Groups, Akop Yepremyan, Magy A. Mekhail, Brian P. Niebuhr, Kristof Pota, Nishanth Sadagopan, Timothy M. Schwartz, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The number of substituted pyridine pyridinophanes found in the literature is limited due to challenges associated with 12-membered macrocycle and modified pyridine synthesis. Most notably, the electrophilic character at the 4-position of pyridine in pyridinophanes presents a unique challenge for introducing electrophilic chemical groups. Likewise, of the few reported, most substituted pyridine pyridinophanes in the literature are limited to electron-donating functionalities. Herein, new synthetic strategies for four new macrocycles bearing the electron-withdrawing groups CN, Cl, NO₂, and CF₃ are introduced. Potentiometric titrations were used to determine the protonation constants of the new pyridinophanes. Further, the influence of …

Laser-Induced Breakdown Spectroscopy For Elemental Analysis In Bioarchaeology And Forensic Anthropology, Kelsi N. Kuehn

USF Tampa Graduate Theses and Dissertations

Within bioarchaeology and forensic anthropology, the current processes of differentiating between individual human skeletal remains are imprecise, costly, and inefficient. A novel analytical technique within anthropology, laser-induced breakdown spectroscopy (LIBS) can aid in the identification of human remains using rapid laser ablation occurring at the micro-scale, making the technique virtually non-destructive to the sample. Considering this, LIBS could offer a superior method for materials discrimination and human identification. This research sought to examine whether LIBS can be used to obtain elemental signatures within bones to distinguish individuals from one another in a rapid, non-destructive manner. Seven human skeletal donors and …

Nf-Κb Inhibitors Attenuate Mcao Induced Neurodegeneration And Oxidative Stress—A Reprofiling Approach, Awais Ali, Fawad Ali Shah, Alam Zeb, Imran Malik, Arooj Mohsin Alvi, Lina Tariq Alkury, Sajid Rashid, Ishtiaq Hussain, Najeeb Ullah, Arif Ullah Khan, Phil Ok Koh, Shupeng Li

All Works

© Copyright © 2020 Ali, Shah, Zeb, Malik, Alvi, Alkury, Rashid, Hussain, Ullah, Ullah Khan, Koh and Li. Stroke is the leading cause of morbidity and mortality worldwide. About 87% of stroke cases are ischemic, which disrupt the physiological activity of the brain, thus leading to a series of complex pathophysiological events. Despite decades of research on neuroprotectants to probe for suitable therapies against ischemic stroke, no successful results have been obtained, and new alternative approaches are urgently required in order to combat this pathological torment. To address these problems, drug repositioning/reprofiling is explored extensively. Drug repurposing aims to identify …

New Catalytic Reactions In Carbohydrate Chemistry, Scott Geringer

Dissertations

Carbohydrates or sugars are some of the most diverse and abundant biological molecules. They are involved in a multitude of processes in the body such as fertilization, cell-cell communication, and cancer metathesis. Because of these vital functions, the study of sugars is rapidly growing field. The field however is limited due to the complex nature of sugars which results in difficulties in obtaining large quantities for study.

Protecting group manipulation is a large emphasis area in carbohydrate chemistry due to the need to selectively protect different functional groups of each molecule during synthesis. Catalytic and selective cleavage of protecting groups …

Synthesis Of Novel Thiazole And Pyrazole Derivatives As Antimicrobial And Anticancer Agents, Rawan Saleh Alnufaie

Student Theses and Dissertations

This thesis contains three chapters. In Chapters One and Two, we report the synthesis of new pyrazole derivatives by using naphthalene-derived and coumarin-derived aldehydes. We have synthesized 61 different pyrazole derivatives in good yield. In the third chapter, a new methodology to synthesize thiazole derivatives is reported. In this methodology, the reaction was performed without column purification and work-up. Readily available starting materials were used with mild reaction conditions. Acetic acid was used as a solvent in this reaction to synthesize 34 new compounds. All these compounds were characterized by using NMR spectroscopy and mass spectrometry. These compounds were tested …

Synthesis Of A Protected 2-Aminocyclobutanone As A Modular Transition State Synthon For Medicinal Chemistry, Thahani S. Habeeb Mohammad, Cory T. Reidl, Matthias Zeller, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

The hydrochloride salt of ɑ-aminocyclobutanone protected as its dimethyl acetal 2,2-dimethoxycyclobutan-1-aminium chloride (3) has been prepared as a modular synthon for convenient access to cyclobutanone-containing lead inhibitors of hydrolase enzymes including serine proteases and metalloproteases. Protected ɑ-aminocyclobutanone 3 was converted to representative amide and sulfonamide-functionalized 2-aminocyclobutanone derivatives. Reaction of the amino acetal 3 with phenyl isothiocyanate afforded the bicyclic urea 1-hydroxyl-2,4-diazabicyclo[3.2.0]heptane-3-thione (9) as confirmed by a single crystal X-ray structure.

Comparative Analysis Of The Human Serine Hydrolase Ovca2 To The Model Serine Hydrolase Homolog Fsh1 From S. Cerevisiae, Jessica S. Bun, Michael D. Slack, Daniel E. Schemenauer, R. Jeremy Johnson

Scholarship and Professional Work - LAS

Over 100 metabolic serine hydrolases are present in humans with confirmed functions in metabolism, immune response, and neurotransmission. Among potentially clinically relevant but uncharacterized human serine hydrolases is OVCA2, a serine hydrolase that has been linked with a variety of cancer-related processes. Herein, we developed a heterologous expression system for OVCA2 and determined the comprehensive substrate specificity of OVCA2 against two ester substrate libraries. Based on this analysis, OVCA2 was confirmed as a serine hydrolase with a strong preference for long-chain alkyl ester substrates (>10-carbons) and high selectivity against a variety of short, branched, and substituted esters. Substitutional analysis …

Fiber-Optic Micro-Probes For Measuring Acidity Level, Temperature, And Antigens, Yinfa Ma, Honglan Shi, Qingbo Yang, Hai Xiao

Chemistry Faculty Research & Creative Works

A pH micro-probe, a temperature micro-probe, and an immuno-based micro-probe each include a shaft for transmuting an input light signal and a tip for inserting into a cell or other substance for measuring pH, temperature, and/or antigens. The pH micro-probe and the temperature micro-probe each include a luminescent material positioned on the tip of the micro-probe. The light signal excites the luminescent material so that the luminescent material emits a luminescent light signal. The luminescent light signal has a property value dependent on the pH or temperature being measured and reflects back through the shaft for being measured by a …

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Atmospheric methanethiol (MeSH_a), dimethyl sulfide (DMS_a) and acetone (acetone_a) were measured over biologically productive frontal waters in the remote southwest Pacific Ocean in summertime 2012 during the Surface Ocean Aerosol Production (SOAP) voyage. MeSH_a mixing ratios varied from below the detection limit (< 10 ppt) up to 65 ppt and were 3 %–36 % of parallel DMS_a mixing ratios. MeSH_a and DMS_a were correlated over the voyage (R²=0.3, slope = 0.07) with a stronger correlation over a coccolithophore-dominated phytoplankton bloom (R²=0.5, slope 0.13). The diurnal cycle for MeSH_a shows similar behaviour to DMS_a with mixing ratios …

Semester-Long Course-Based Research Project In Second-Semester Organic Chemistry: Synthesizing Potential Lead Compounds For The Treatment Of A Neglected Tropical Disease, Kerry L. Barnett, Kevin M. Shea, Catherine Mcgeough, Kristine Trotta, Steven A. Williams, Minh Ly, Kathryn Aloisio

Chemistry: Faculty Publications

A semester-long research project for second-semester organic chemistry lab sections was developed. Student projects were based on preliminary data from faculty research that suggested the natural product neurolenin B to be a treatment for lymphatic filariasis. Students isolated neurolenins from the Central American plant Neurolaena lobata and proposed syntheses of previously unknown analogues using reactions learned in first- and second-semester organic chemistry. Using literature-based procedures, students ran reactions on neurolenins and analyzed their results by TLC and NMR spectroscopy. The semester culminated with a public poster session and final report using the Organic Letters template. Students in a total of …

Ambient Air Quality In The Kathmandu Valley, Nepal, During The Pre-Monsoon: Concentrations And Sources Of Particulate Matter And Trace Gases, Md Robiul Islam, Thilina Jayarathne, Isobel J. Simpson, Benjamin Werden, John Maben, Ashley Gilbert, Puppala S. Praveen, Sagar Adhikari, Arnico K. Panday, Maheswar Rupakheti, Donald R. Blake, Robert J. Yokelson, Peter F. Decarlo, William C. Keene, Elizabeth A. Stone

Chemistry and Biochemistry Faculty Publications

The Kathmandu Valley in Nepal is a bowl-shaped urban basin that experiences severe air pollution that poses health risks to its 3.5 million inhabitants. As part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE), ambient air quality in the Kathmandu Valley was investigated from 11 to 24 April 2015, during the premonsoon season. Ambient concentrations of fine and coarse particulate matter (PM2:5 and PM10, respectively), online PM1, inorganic trace gases (NH3, HNO3, SO2, and HCl), and carbon-containing gases (CO2, CO, CH4, and 93 nonmethane volatile organic compounds; NMVOCs) were quantified at a semi-urban location near the center of …

Restructuring A General College Chemistry Sequence Using The Acs Anchoring Concepts Content Map, Scott A. Reid

Chemistry Faculty Research and Publications

Many STEM (science, technology, engineering, and mathematics) disciplines require a two-semester sequence of introductory college chemistry, which are thus critical gateway courses to a variety of majors. Recognizing the benefit to educators of a structure of content learning across the chemistry curriculum, in 2012, the American Chemical Society (ACS) developed the Anchoring Concepts Content Map, or ACCM. The development and subsequent revision of the general chemistry ACCM inspired the restructuring of our first-year chemistry sequence. Thus our CHEM 1001 and 1002 courses, taught in an atoms-first framework, were reorganized into a set of nine modules, each intentionally linked to one …

Interactions Between The Azoarcus Ribozyme And Manganese (Ii) Divalent Cations, Joshua Martwick

University Honors Theses

The RNA world hypothesis suggests that RNA systems were the first form of life on the planet, beginning to appear approximately 4 billion years ago. Group I introns are self-splicing RNA elements in extant organisms and use Mg²⁺ as the principle divalent cation to promote catalysis. The group I intron ribozyme from Azoarcus is frequently used in origin of life studies, partially due to its autocatalytic abilities - the Azoarcus ribozyme is able to be broken into fragments and reassemble itself into its fully functional ribozyme. Previous work identified metal binding sites on the Azoarcus ribozyme which use both …

Development Of Hplc Separation Method Of Ginsenosides On A Polyvinyl Alcohol-Bonded Stationary Phase, A. B. Soliev, A. T. Adylova, I. Yu. Abdurakhmonov, G. N. Artikova

Karakalpak Scientific Journal

A simple high performance liquid chromatographic assay for the simultaneous quantitative analysis of seven ginsenosides, Rb1, Rb2, Rc, Rd, Re, Rf and Rg1 in commercial ginseng products is described. Chromatographic separation of the analytes was achieved in less than 20 min using a polyvinyl alcohol-bonded column with UV detection at 203 nm. Optimization of chromatographic conditions was determined by a three-factor central composite design, the variables being the percentage of acetonitrile in the mobile phase, column temperature and flow rate. A full quadratic model was found to be adequate in describing the separation of ginsenosides on the polyvinyl alcohol-bonded stationary …

Valorization Of Carrot Processing Waste, Alexandra M. Duval

Master's Theses

Commercial carrot processors produce up to 175,000 tons of carrot waste annually. Carrot Mash (CM) is the term referring to the waste by-product of peeled baby carrot processing. Transportation of carrot processing waste is expensive due to its high- water content (approx. 83-95%). High in bioactive compounds (carotenoids) and dietary fibers, it is expected that its conversion into a value-added by-product is of interest to the carrot processing industry. Hemicellulose-rich plant materials have proven to be a source of oligosaccharides, which are known for their beneficial prebiotic activity. The objectives of this research were to: 1) determine the effect of …

Infrared Spectroelectrochemistry Of Iron-Nitrosyl Triarylcorroles. Implications For Ligand Noninnocence, Md. Hafizur Rahman, Michael D. Ryan, Hugo Vazquez-Lima, Abraham Alemayehu, Abhik Ghosh

Chemistry Faculty Research and Publications

Recent DFT calculations have suggested that iron nitrosyl triarylcorrole complexes have substantial {FeNO}⁷–corrole^•2– character. With this formulation, reduction of Fe(C)(NO) complexes, where C = triarylcorrole, should be centered on the corrole macrocycle rather than on the {FeNO}⁷ moiety. To verify this proposition, visible and infrared spectroelectrochemical studies of Fe(C)(NO) were carried out and the results were interpreted using DFT (B3LYP/STO-TZP) calculations. The first reduction of Fe(C)(NO) led to significant changes in the Soret and Q-band regions of the visible spectrum as well as to a significant downshift in the ν_NO and changes in the corrole …

Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC− In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein

Faculty Publications

System x_c⁻ exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System x_c⁻ is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H₂O₂) triggers the translocation of System x_c⁻ to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in ³⁵S-L-cystine uptake following a 10 min exposure to 0.3 mM H₂O₂. This effect was dose-dependent with an EC₅₀ for …

A Halogen Bonding Perspective On Iodothyronine Deiodinase Activity, Eric S. Marsan, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Iodothyronine deiodinases (Dios) are involved in the regioselective removal of iodine from thyroid hormones (THs). Deiodination is essential to maintain TH homeostasis, and disruption can have detrimental effects. Halogen bonding (XB) to the selenium of the selenocysteine (Sec) residue in the Dio active site has been proposed to contribute to the mechanism for iodine removal. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known disruptors of various pathways of the endocrine system. Experimental evidence shows PBDEs and their hydroxylated metabolites (OH-BDEs) can inhibit Dio, while data regarding PCB inhibition are limited. These xenobiotics could inhibit Dio activity by competitively …

Hydrophilic Porphyrins Based Chemosensors For First Transition Series Metal Ions [Chemistry], Sunaina Singh

Open Educational Resources

General Chemistry is a two-semester course (General Chemistry I, SCC 201 and General Chemistry II, SCC 202) required for majors in Biology and Environmental Sciences.

This lab experiment, aligned to LaGuardia Community College’s Inquiry and Problem Solving Core Competency and Written Communication Ability was designed for General Chemistry I (SCC 201 Honors) course. Honors courses in LaGuardia emphasize critical thinking, analytical writing, and introduce students to research. This lab experiment provides an opportunity for students to engage in hands-on laboratory work, to develop laboratory skills, and to conduct research in the classroom by using two water soluble porphyrins to detect …

Asking Why: Analyzing Students' Explanations Of Organic Chemistry Reaction Mechanisms Using Lexical Analysis And Predictive Logistic Regression Models, Amber J. Dood

USF Tampa Graduate Theses and Dissertations

In order to evaluate student understanding of chemical reactions and reaction mechanisms, it is necessary to ask students to construct written or oral explanations of mechanistic representations. Studies have shown that students can reproduce pictorial representations of organic chemistry mechanisms without understanding the meaning of the representations. Grading written assessments is time-consuming, which limits their use in large-lecture courses. To address this limitation, lexical analysis and logistic regression techniques can be used to develop models that predict human scoring for constructed-response items. In this dissertation, students’ responses to constructed-response items about what is happening and why in organic chemistry reaction …

Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan

LSU Doctoral Dissertations

The impacts of sea-level rise and hydrologic manipulation are threatening the stability of coastal marshes throughout the world, thereby increasing the potential for re-mineralization of soil organic matter (SOM) in these systems. Such threats have prompted marsh restoration efforts, particularly in coastal Louisiana, yet it is unclear how the slowly decomposing (refractory) and quickly decomposing (labile) fractions of SOM may be differentially affected by different approaches to marsh restoration. Additionally, otherwise labile compounds may accumulate in the soil via a range of protective mechanisms, including rapid burial and association with organic compounds that are thought to enhance soil aggregation, such …

Yeast Copper Proteins And Reactive Oxygen Species In Effecting Lifespan, Megan Bestwick

Post-Grant Reports

Mitochondria are essential organelles in most eukaryotic cells because of their role in metabolism and the production of ATP by the oxidative phosphorylation (OXPHOS) pathway, as well as other key cellular processes. Metal cofactors, such as copper (Cu) and iron (Fe), are incorporated into OXPHOS protein complexes of yeast located within the inner membrane of the mitochondria. Misincorporation or modulation of these available metals in mitochondrial enzymes leads to the production of reactive oxygen species (ROS). ROS are reactive molecules containing oxygen such as peroxides, superoxide, and hydroxyl radicals. Yeast are a good model for studying aging and the effect …

The Allometry Of Daily Energy Expenditure In Hummingbirds: An Energy Budget Approach, Anushu Shankar, Donald R. Powers, Liliana M. Dávalos, Catherine H. Graham

Faculty Publications - Department of Biological & Molecular Science

1. Within-clade allometric relationships represent standard laws of scaling between energy and size, and their outliers provide new avenues for physiological and ecological research. According to the metabolic-level boundaries hypothesis, metabolic rates as a function of mass are expected to scale closer to 0.67 when driven by surface-related processes (e.g. heat or water flux), while volume-related processes (e.g. activity) generate slopes closer to one.

2. In birds, daily energy expenditure (DEE) scales with body mass (M) in the relationship log (DEE)=2.35+0.68×log (M), consistent with surface-level processes driving the relationship. However, taxon-specific patterns differ from the scaling slope of all birds. …

Force Field Development Of Β-Lactam Class Antibiotics, Trevor Heinzmann

SMU Journal of Undergraduate Research

Molecular dynamics (MD) simulation is a computational chemistry technique used to observe how a molecular system behaves as time passes. MD is based on solving Newton’s equations of motion. This requires the use of force fields to describe the potential energy function of each different molecule type in molecular system. In order to develop a force field, charges, bonds, angles, and dihedrals must be parameterized to fit quantum mechanics (QM) data. By basing the force field on QM data, MD simulations have higher accuracy while still using the low computational cost of molecular mechanics. This project focuses on developing well-fit …

Quantitative Trait Loci (Qtl) Underlying Phenotypic Variation In Bioethanol-Related Processes In Neurospora Crassa, Joshua C. Waters, Deval Jhaveri, Justin C. Biffinger, Kwangwon Lee

Chemistry Faculty Publications

Bioethanol production from lignocellulosic biomass has received increasing attention over the past decade. Many attempts have been made to reduce the cost of bioethanol produc- tion by combining the separate steps of the process into a single-step process known as consolidated bioprocessing. This requires identification of organisms that can efficiently decompose lignocellulose to simple sugars and ferment the pentose and hexose sugars lib- erated to ethanol. There have been many attempts in engineering laboratory strains by add- ing new genes or modifying genes to expand the capacity of an industrial microorganism. There has been less attention in improving bioethanol-related processes …

Assessing Differences Between Three Virtual General Chemistry Experiments And Similar Hands-On Experiments, Cory Hensen, Gosia Glinowiecka-Cox, Jack Barbera

Chemistry Faculty Publications and Presentations

To date the efficacy of virtual experiments is not well understood. To better understand what differences may exist between a hands-on learning environment and a virtual learning environment, three experiments were chosen for investigation. For each experiment, approximately half of the students completed a hands-on version of the experiment and the other half completed a virtual version. After completing the given experiment, students were compared on: their ability to meet the learning objectives for that experiment, their responses to six affective scales, and their grade on a laboratory report. Differences were found on four learning objectives. Two of these learning …

Polymers For Extrusion‐Based 3d Printing Of Pharmaceuticals: A Holistic Materials–Process Perspective, Mohammad A. Azad, Deborah Olawuni, Georgia Kimbell, Abu Zayed Badruddoza, Md. Shahadat Hossain, Tasnim Sultana

Publications and Research

Three dimensional (3D) printing as an advanced manufacturing technology is progressing to be established in the pharmaceutical industry to overcome the traditional manufacturing regime of ʹone size fits for allʹ. Using 3D printing, it is possible to design and develop complex dosage forms that can be suitable for tuning drug release. Polymers are the key materials that are necessary for 3D printing. Among all 3D printing processes, extrusion‐based (both fused deposition modeling (FDM) and pressure‐assisted microsyringe (PAM)) 3D printing is well researched for pharmaceutical manufacturing. It is important to understand which polymers are suitable for extrusion‐based 3D printing of pharmaceuticals …

Electrochemical Studies Of Cobalt(Ii) Diphenylazodioxide Complexes, Lakshmi Balarama, Kylin A. Emhoff, Ahmed M.H. Salem, Jovana Hanna, Mohamed N. Alsabony, Mekki Bayachou, Jerry Mundell, W. Christropher Boyd

Chemistry Faculty Publications

The electrochemical behavior of the unusual cobalt(II) diphenylazodioxide complex salts [Co(az)₄](PF₆)₂ 1 and [Co(bpy)(az)₂](PF₆)₂ 2 has been studied by cyclic voltammetry. Each complex displays two quasireversible redox couples, which are proposed to correspond to a reduction of Co(II) to Co(I), followed by a ligand-based reduction. Irreversible reductions of 1 are observed at more negative potentials, and are proposed to arise from deposition of elemental Co and the decomposition of transiently formed Co(-I) species. Spectroelectrochemical experiments on both 1 and 2, involving electrolytic reduction followed by reoxidation, are consistent with …

Competition Between Intra And Intermolecular Triel Bonds. Complexes Between Naphthalene Derivatives And Neutral Or Anionic Lewis Bases, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

A TrF₂ group (Tr = B, Al, Ga, In, Tl) is placed on one of the α positions of naphthalene, and its ability to engage in a triel bond (TrB) with a weak (NCH) and strong (NC⁻) nucleophile is assessed by ab initio calculations. As a competitor, an NH₂ group is placed on the neighboring C^α, from which point it forms an intramolecular TrB with the TrF₂ group. The latter internal TrB reduces the intensity of the π-hole on the Tr atom, decreasing its ability to engage in a second external TrB. The …