Digital Commons Network^™

Preparation Of Au/Ag Nanoshells Through A Galvanic Replacement Reaction, Elizabeth Maschmeyer

All Capstone Projects

It generally requires solid metal templates of hollow metal structures with uniform morphology by the present galvanic replacement mediated-growth approaches. In this project report, we present a new and simple approach for the controllable synthesis of Au/Ag alloy nanoshells (NSs) by applying galvanic replacement reaction on hollow Ag template in the presence of gold salt. High quality thiol-coated spherical shape Au/Ag NSs were produced via this new synthetic approach and the hollow interior of the Ag template is very well preserved during the galvanic replacement reaction. Plasmonic property measurements reveal that Au/Ag NSs exhibit strong absorption peak and more importantly, …

Organic Chemistry I Lab (Clayton), Tatiana Krivosheev, Caroline Sheppard, Patricia Todebush, Bram Boroson, Justin Mays

Chemistry Grants Collections

This Grants Collection for Organic Chemistry I was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Reactivity Of (1-Methoxycarbonylpentadienyl)Iron(1+) Cations With Hydride, Methyl, And Nitrogen Nucleophiles, Yuzhi Ma, Young K. Yun, Julie L. Wondergem, Anobick Sar, Jayapal Reddy Gone, Sergey V. Lindeman, William A. Donaldson

Chemistry Faculty Research and Publications

The reaction of tricarbonyl and (dicarbonyl)triphenylphosphine (1-methoxycarbonyl-pentadientyl)iron(1+) cations 7 and 8 with methyl lithium, NaBH₃CN, or potassium phthalimide affords (pentenediyl)iron complexes 9a-c and 11a-b, while reaction with dimethylcuprate, gave (E,Z-diene)iron complexes 10 and 12. Oxidatively induced-reductive elimination of 9a-c gave vinylcyclopropanecarboxylates 17a-c. The optically active vinylcyclopropane (+)-17a, prepared from (1S)-7, undergoes olefin cross-metathesis with excess (+)-18 to yield (+)-19, a C9C16 synthon for the antifungal agent ambruticin. Alternatively reaction of 7 with methanesulfonamide or …

Toward Reliable Modeling Of S-Nitrosothiol Chemistry: Structure And Properties Of Methyl Thionitrite (Ch3sno), An S-Nitrosocysteine Model, Dmitry Khomyakov, Qadir K. Timerghazin

Chemistry Faculty Research and Publications

Methyl thionitrite CH₃SNO is an important model of S-nitrosated cysteine aminoacid residue (CysNO), a ubiquitous biological S-nitrosothiol (RSNO) involved in numerous physiological processes. As such, CH₃SNO can provide insights into the intrinsic properties of the —SNO group in CysNO, in particular, its weak and labile S—N bond. Here, we report an ab initio computational investigation of the structure and properties of CH₃SNO using a composite Feller-Peterson-Dixon scheme based on the explicitly correlated coupled cluster with single, double, and perturbative triple excitations calculations extrapolated to the complete basis set limit, CCSD(T)-F12/CBS, with a number of …

Studies In Directed Catalytic Asymmetric Hydroboration Of 1,2-Disubstituted Unsaturated Amide, Shuyang Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

The Rh-catalyzed, substrate directed catalytic asymmetric hydroboration of γ,δ-unsaturated amides provides a direct route to enantioenriched acyclic secondary γ-borylated carbonyl derivatives with high regio- and enantioselectivity. The catalytic condition optimization and substrate scope study is discussed, including the effects in catalytical asymmetric hydroboration on pre-installed chiral γ,δ-unsaturated amides. A mechanistic study from kinetic approach by graphical manipulation (reaction progress kinetic analysis for substrate orders and normalized time analysis for catalyst order.) was discussed in this thesis

Advisor: Professor James M. Takacs

Principles Of Chemistry I Lab (Clayton), Tatiana Krivosheev, Caroline Sheppard, Patricia Todebush, Bram Boroson, Justin Mays

Chemistry Grants Collections

This Grants Collection for Principles of Chemistry I was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Principles Of Chemistry Ii Lab (Clayton), Tatiana Krivosheev, Caroline Sheppard, Patricia Todebush, Bram Boroson, Justin Mays

Chemistry Grants Collections

This Grants Collection for Principles of Chemistry II was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Organic Chemistry Ii Lab (Clayton), Tatiana Krivosheev, Caroline Sheppard, Patricia Todebush, Bram Boroson, Justin Mays

Chemistry Grants Collections

This Grants Collection for Organic Chemistry II was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

• Linked Syllabus
• Initial Proposal
• Final Report

Review Of Ligand Specificity Factors For Cyp1a Subfamily Enzymes From Molecular Modeling Studies Reported To-Date, Jayalakshmi Sridhar, Navneet Goyal, Jiawang Liu, Maryam Foroozesh

Faculty and Staff Publications

The cytochrome P450 (CYP) family 1A enzymes, CYP1A1 and CYP1A2, are two of the most important enzymes implicated in the metabolism of endogenous and exogenous compounds through oxidation. These enzymes are also known to metabolize environmental procarcinogens into carcinogenic species, leading to the advent of several types of cancer. The development of selective inhibitors for these P450 enzymes, mitigating procarcinogenic oxidative effects, has been the focus of many studies in recent years. CYP1A1 is mainly found in extrahepatic tissues while CYP1A2 is the major CYP enzyme in human liver. Many molecules have been found to be metabolized by both of …

Acylation Of Superoxide Dismutase 1 (Sod1) At K122 Alters Sod1 Localization And Sod1-Mediated Inhibition Of Mitochondrial Respiration, Nathan William Rodriguez

Theses and Dissertations

Cu/Zn Superoxide Dismutase (SOD1), is a ubiquitous antioxidant enzyme with several emerging roles outside of its canonical function. SOD1 is also emerging in central roles in cancer and neurodegenerative pathologies. Little is known about SOD1 regulation, particularly at a post-translational level. Post-translational modifications (PTMs) play an important role in enabling proteins to rapidly respond to their environment. Therefore, identifying specific PTMs involved in protein regulation represents a powerful opportunity to interfere with any associated pathologies. This work employs proteomics to identify mechanisms of post-translation regulation on cell survival signaling proteins. We focused on SOD1, which protects cells from oxidative stress. …

Functional And Structural Studies Of Cytochromes P450 By Resonance Raman Spectroscopy, Yilin Liu

Dissertations (1934 -)

Cytochrome P450 is a broad class of heme monooxygenase enzymes which catalyze various oxidative transformations. There are two main kinds of mammalian P450s: steroidogenic and drug metabolizing P450s. The first project involves a steroidogenic P450, CYP17A1, occupying a central role in the biosynthesis of steroid hormones. It catalyzes hydroxylation reaction on pregnenolone and progesterone, generating 17OH-pregnenolone and 17OH-progesterone, presumably utilizing a “Compound I” species. However, these hydroxylated products can be further processed in a second oxidative cycle to cleave the C17–C20 bond to form dehydroepiandrosterone or androstenedione, respectively, a crucial step in androgen production. Interestingly, it is well known that …

Redox And Spectroscopic Properties Of Protonated Species Of Iron Porphyrin Nitroxlys And Their Analogues, Md. Hafizur Rahman

Dissertations (1934 -)

Nitrite reduction to ammonia or nitrous oxide involves a series of electron transfer and protonation steps which are carried out by assimilatory or dissimilatory nitrite reductases. In the assimilatory process, nitrite incorporated into the biomass while in the dissimilatory process, it is excreted from the cell and the reaction is a source of energy. The complexes that will be studied in this work are models for assimilatory (siroheme) and dissimilatory (heme d1 ) nitrite reductases. Iron porphyrin nitrosyls were reduced in the presence of weak acids such as phenol and substituted phenols. Voltammetric techniques such as cyclic and rotating ring …

Design And Synthesis Of Selective Estrogen Receptor Β Agonists And Their Pharmacology, K. L. Iresha Sampathi Perera

Dissertations (1934 -)

Estrogens (17β-estradiol, E2) have garnered considerable attention in influencing cognitive process in relation to phases of the menstrual cycle, aging and menopausal symptoms. However, hormone replacement therapy can have deleterious effects leading to breast and endometrial cancer, predominantly mediated by estrogen receptor-alpha (ERα) the major isoform present in the mammary gland and uterus. Further evidence supports a dominant role of estrogen receptor-beta (ERβ) for improved cognitive effects such as enhanced hippocampal signaling and memory consolidation via estrogen activated signaling cascades. Creation of the ERβ selective ligands is challenging due to high structural similarity of both receptors. Thus far, several ERβ …

Fundamental Studies And Applications Of Ambient Plasma Ionization Sources For Mass Spectrometry, Wade C. Ellis

Theses and Dissertations

The field of ambient desorption/ionization mass spectrometry (ADI-MS) has existed for over a decade. ADI-MS is a technique that offers benefits including fast analysis time, simple ionization sources that are easily constructed, and little to no required sample preparation. The research presented here describes efforts to better understand plasma-based ADI-MS sources and to explore the use of hydrogen-doped plasma gases with these sources. The use of hydrogen-doped argon (H₂/Ar) and hydrogen-doped helium (H₂/He) as plasma gases for a dielectric barrier discharge (DBD) and an AC glow discharge is presented first. When using the DBD, the intensity …

Generating Enzyme And Radical‐Mediated Bisubstrates As Tools For Investigating Gcn5‐Related N‐Acetyltransferases, Cory T. Reidl, Karolina A. Majorek, Joseph Dang, David Tran, Kristen Jew, Melissa Law, Yasmine Payne, Wladek Minor, Daniel P. Becker, Misty L. Kuhn

Chemistry: Faculty Publications and Other Works

Gcn5‐related N‐acetyltransferases (GNATs) are found in all kingdoms of life and catalyze important acyl transfer reactions in diverse cellular processes. While many 3D structures of GNATs have been determined, most do not contain acceptor substrates in their active sites. To expand upon existing crystallographic strategies for improving acceptor‐bound GNAT structures, we synthesized peptide substrate analogs and reacted them with CoA in PA4794 protein crystals. We found two separate mechanisms for bisubstrate formation: (a) a novel X‐ray induced radical‐mediated alkylation of CoA with an alkene peptide and (b) direct alkylation of CoA with a halogenated peptide. Our approach is widely …

Analysis Of Ultrafast Transient Absorption Spectroscopy Data Using Integrative Data Analysis Platform: 1. Data Processing, Fitting, And Model Selection, Evgenii L. Kovrigin

Chemistry Faculty Research and Publications

This manuscript describes a workflow for analysis of transient absorption (TA) spectroscopy data using Integrative Data Analysis Platforms (IDAP) software package. Time-dependent spectral series are analyzed through evaluation of the isosbestic point and kinetics of excited state and ground-state bleach decays. Model fitting and selection based on Akaike's Information Criterion is discussed. As a practical example, we analyze excitation decays of a common protein label, Alexa Fluor 647.

Characterization Of 3-Ester And 3-Carbamate Derivatives Of N-Acetyl-D-Glucosamine And Their Use In Controlled Drug Delivery, Consuelo Garcia

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are a class of compounds which reversibly form a network that traps solvents to form gels. Gelation by LMWGs is driven solely by non-covalent interactions such as hydrogen bonding, π - π stacking, and hydrophobic interactions. LMWGs can be designed such that the gel-sol and sol-gel transitions happen as a response to a specific stimulus. These stimulus responsive gels or “smart” gels can be used in a wide variety of applications including tissue regeneration, biosensing, and controlled drug delivery.

Among the different types of compounds that are LMWGs, carbohydrate based systems are especially interesting. Carbohydrates …

Lignin Contribution To The Global Carbon Pool: Investigating The Abiotic Modification Of Lignin By Reactive Oxygen Species, Derek Charles Waggoner

Chemistry & Biochemistry Theses & Dissertations

Evidence suggests that reactive oxygen species (ROS), largely generated through photochemical processes, are important in transforming the chemical composition of the large pool of terrestrially-derived dissolved organic matter (DOM) exported from land to water annually. However, due to the challenges inherent in isolating the effects of individual ROS on DOM composition, the role of ROS in the photochemical alteration of DOM remains poorly characterized. The main focus of the studies within this dissertation aim to more thoroughly characterize the alterations to lignin, used as an analog for terrestrial DOM, resulting from reactions with ROS.

To investigate the possibility that the …

Formulation, Characterisation And Stability Assessment Of A Food Derived 1 Tripeptide, Leucine-Lysine-Proline Loaded Chitosan Nanoparticles, Minna Khalid Danish, Giuliana Vozza, Hugh Byrne, Jesus Maria Frias, Sinead Ryan

Articles

The chicken or fish derived tripeptide, Leucine-Lysine-Proline (LKP), inhibits the Angiotensin Converting Enzyme and may be used as an alternative treatment for pre-hypertension. However, it has low permeation across the small intestine. The formulation of LKP into a nanoparticle (NP) has the potential to address this issue. LKP-loaded NPs were produced using an ionotropic gelation technique, using chitosan (CL113). Following optimisation of unloaded NPs, a mixture amount design was constructed using variable concentration of CL113 and tripolyphosphate at a fixed LKP concentration. Resultant particle sizes ranged from 120-271 nm, zeta potential values from 29-37 mV and polydispersity values from 0.3-0.6. …

Antifungal Potential Of Copper(Ii), Manganese(Ii) And Silver(I) 1,10-Phenanthroline Chelates Against Multidrug-Resistant Fungal Species Forming The Candida Haemulonii Complex: Impact On The Planktonic And Biofilm Lifestyles, Rafael M. Gandra, Pauraic Mc Carron, Mariana F. Fernandes, Lívia S. Ramos, Thaís P. Mello, Ana Carolina Aor, Marta H. Branquinha, Malachy Mccann, Michael Devereux, André L. S. Santos

Articles

Candida haemulonii, Candida haemulonii var. vulnera and Candida duobushaemulonii, which form the C. haemulonii complex, are emerging etiologic agents of fungal infections known to be resistant to the most commonly used antifungals. The well-established anti-Candida potential ofmetal complexes containing 1,10-phenanthroline (phen) ligands encouraged us to evaluate different copper(II), manganese(II), and silver(I) phen chelates for their ability to inhibit planktonic growth and biofilm of C. haemulonii species complex. Two novel coordination complexes, {[Cu(3,6,9-tdda)(phen)2].3H2O.EtOH}n and [Ag2(3,6,9-tdda)(phen)4].EtOH (3,6,9-tddaH2 = 3,6,9-trioxaundecanedioic acid), were synthesized in a similar fashion to the other, previously documented, sixteen copper(II), manganese(II), and silver(I) chelates employed herein. Three isolates of …

Effect Of Facial Encumbrance On Excimer Formation And Charge Resonance Stabilization In Model Bichromophoric Assemblies, Brandon Uhler, Maxim V. Ivanov, Damian Kokkin, Neil Reilly, Rajendra Rathore, Scott A. Reid

Chemistry Faculty Research and Publications

Excimer formation and charge resonance stabilization in covalently linked bichromophoric systems with flexible spacers are important processes relevant to biochemistry and functional materials. Requiring a π-stacked cofacial arrangement of a pair of aromatic molecules at a van der Waals contact, the underlying geometrical reorganization that accompanies these events continues to be debated. Here we use a variety of methods including two-color resonant two-photon ionization spectroscopy (2CR2PI), ion yield measurements, hole-burning spectroscopy (HB), and laser-induced fluorescence (LIF) excitation and emission spectroscopy to compare the gas-phase spectroscopy and dynamics of the van der Waals dimers of fluorene, 9-methylfluorene (MF), and 9,9′-dimethylfluorene (F1). …

Function Of Ric-8a In G Protein E+- Subunit Biogenesis, Barry Willardson

Journal of Undergraduate Research

1. Grant Ludlam. The MEG award helped support Grant’s work from January 2015 through August 2016. During this time Grant has worked on three projects. He investigated the role of Ric8A in the folding of the G protein a subunit and its assembly into the G protein heterotrimeric complex. Unfortunately, his results showed that deletion of Ric8A in the photoreceptor cells of mice did not affect G protein signaling. As a result, he changed his research focus to determining the structure of the BBSome core complex. He assisted a graduate student, Takuma Aoba, in this work. They used a combination of …

Mentoring Undergraduates At The Intersection Of Organic Synthesis And Peptide Science, Steven L. Castle

Journal of Undergraduate Research

Our academic goals were threefold. First, we aimed to synthesize building blocks and begin assembling them to construct the anticancer peptide yaku’amide A (YA, Figure 1). Our purposes in synthesizing YA were to develop new chemical reactions suitable for efficiently preparing its unusual amino acids (shown in red and blue in Figure 1), and synthesize simplified analogues for use in studies designed to reveal its biological target and mode of action. Our second academic goal was derived from the first and involved investigating the ability of bulky dehydroamino acids (i.e., the amino acids of YA shown in blue in Figure …

Investigating Students’ Basic Needs And Motivation In College Chemistry Courses With The Lens Of Self-Determination Theory, Yujuan Liu

USF Tampa Graduate Theses and Dissertations

More graduates in science, technology, engineering, and mathmetics (STEM) fields are needed to keep our nation’s preeminance in the global fields of technology and science. However, fewer than 40% of students who intend to major in STEM fields when entering college complete a STEM degree. Therefore, it is important to explore factors to improve student persistence in STEM fields at the college level as well as to understand the interrelationship between student motivation, academic achievement, and persistence. Motivation is strongly associated with student achievement and persistence; meanwhile, academic achievement can also affect persistence. Self-determination theory (SDT) represents a framework of …

Ionic Liquid-Supported Tempo/Polymeric Ionic-Liquid/Carbon Black Ternary Composites: Preparations And Applications In Electrochemical Oxidation Of Alcohols, Xin Lin, Cao-Cao Sun, Zhi-Rong Liu, Cheng-Chu Zeng

Journal of Electrochemistry

To effectively recover redox catalyst and supporting electrolyte, a novel ternary composite consisting of ionic liquid-supported TEMPO, polymeric ionic-liquid and carbon black was prepared. The ionic-liquid supported redox catalyst TEMPO-IL-BF₄ was firstly synthesized from 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and followed by the reaction of polydimethyldiallylammonium chloride (PDDA) and bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) to form poly[diallyldimethylammonium bis(trifluoromethanesulfonyl)imide] (PDDA(Tf₂N)). A combination of the above mentioned two synthesized materials and carbon black afforded to obtain the ternary composite, which was used as the recoverable supporting electrolyte and mediator for the electrochemical oxidation of alcohol. The results indicate that various alcohols could be oxidized …

Study On The Electrochemical Redox Mechanism Of Emodin, Dan Li, Bao-Kang Jin

Journal of Electrochemistry

The electrochemical reduction of emodin (Q) has been investigated in acetonitrile by cyclic voltammetry (CV), IR spectroelectrochemistry cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA) techniques. It was found that anion radical Q^•− interacted with neutral Q to form dimer Q₂^•− which was further reduced to Q₂²⁻ at more negative potentials. A two-step one-electron process involving electrochemical reductions of Q₂²⁻ to form Q₂³⁻ in the first step and Q₂⁴⁻ in the second step, corresponding to the two cathodic peaks of C₃ and C₄ in CV curves was …

Wastewater Treatment Process Based On Microbial Electrochemistry: Opportunities And Challenges, Wei-Hua He, Jia Liu, Hai-Man Wang, Yu-Jie Feng

Journal of Electrochemistry

Microbial electrochemical technology (MET) has drawn great attention for its characteristics of synergetic pollution removal and energy recovery of wastewater. In the last decade, significant developments in microbial electrochemical system (MES) have been made in the aspects of electron transfer mechanism, microbial community analysis, function expansion, low-cost electrode materials and scaled-up constructions. However, the feasibility of MET as a wastewater treatment process has been controversial so far. In this paper, the characteristics of MET were systematically compared with anaerobic and aerobic processes from the application point of view in the aspects of pollution degradation and energy recovery processes. The MET-based …

Electrocatalysis Of Nanotin Dioxide In The Battery Reaction Of Zinc-Nitrobenzene, Xu-Guo Tu, Xiang-Yu Ma, Rui-Nan He, Xiao-Juan Wang, Chen Ling, Yun-Xia Sun, Song Chen

Journal of Electrochemistry

The tin dioxide (SnO₂) nanoparticles were synthesized by using a simple hydrothermal route in the presence of tetrapropyl ammonium bromide (TPAB) as a surfactant. Accordingly, the titanium mesh based SnO₂ catalyst electrode was prepared. The morphologies and structures of SnO₂ nanostructures were characterized by scanning electron microscopy and X-ray diffraction spectrometry. The influences of reactant concentration, reaction temperature and time on the morphology of the products were investigated in detail. The electrocatalytic performance of SnO₂ for the reduction of nitrobenzene with zinc was studied. Possible formation process and growth mechanism for such hierarchical SnO_{2 …}

The Quantification Of Cocaine From The Erythroxylum Coca Plant And The Comparison On High Performance Liquid Chromatography And Gas Chromatography Mass Spectroscopy As An Analytical Method., Tuesday James

Student Theses

Cocaine is derived from the Erythroxylum coca plant, is a highly addictive stimulant abused all over the world. There are two types of Erythroxylum coca plants that produce cocaine; the E. Coca and E. Novogranatense. Cocaine exists as the salt, and the freebase which is typically referred to as “crack” due to the crackling sound it makes when heated. It is popular because it is inexpensive and easily available on the streets, mainly in poor urban areas. The purpose of this project was to determine the amount of cocaine that can be extracted from E.coca and to assess which analytical …

Toward The Synthesis Of Naphthalene-Bridged Bis-Triazole Bimetallic Complexes, Sean M. Johnson

USF Tampa Graduate Theses and Dissertations

Bimetallic complexes are known to have unique electronic properties and are used in a variety of organic transformations as catalysts. The use of naphthalene-bridged bis- triazoles (NBT) for bimetallic complexes is unknown. NBTs have the unique property of being fluorescent stemming from a twisted intramolecular charge transfer. With the non- coplanar geometry and the distance between the 1,2,3-triazole rings, we hypothesized that 1,8-bis(4-phenyl-2H-1,2,3-triazol-2-yl)naphthalene (12) would be a suitable ligand to synthesize a bimetallic complex. The synthesis of 12 was optimized for large scale synthesis and was synthesized on a 78 mmol scale in 15% total yield. Metal complexation …