Digital Commons Network^™

Antibacterial Activities Of Wasabi Against Escherichia Coli O157:H7 And Staphylococcus Aureus, Zhongjing Lu, Christopher Dockery, Michael Crosby, Katherine Chavarria, Brett Patterson, Matthew Giedd

Faculty Articles

Escherichia coli O157:H7 and Staphylococcus aureus are two of the major pathogens frequently involved in foodborne outbreaks. Control of these pathogens in foods is essential to food safety. It is of great interest in the use of natural antimicrobial compounds present in edible plants to control foodborne pathogens as consumers prefer more natural “green” foods. Allyl isothiocyanate (AITC) is an antimicrobial compound naturally present in wasabi (Japanese horseradish) and several other edible plants. Although the antibacterial effects of pure AITC and wasabi extract (essential oil) against several bacteria have been reported, the antibacterial property of natural wasabi has not been …

Studies In The Asymmetric Synthesis Of The C21-C34 Fragment Of The Natural Product, Antascomicin B, Brian Lee Walker

Graduate Theses and Dissertations

This dissertation describes studies in the asymmetric synthesis of the C21 – C34 fragment of the natural product, antascomicin B. Antascomicin B is structurally related to FK506, binds strongly to FKBP12, yet does not shown immunosuppressive activity. Small ligand FKBP12 binding complexes were shown to have potent neuroprotective and neuroregenerative properties in mouse models of Parkinson’s disease. The highlighted chemical reactions include an asymmetric transfer hydrogenation (ATH), Ireland-Claisen rearrangement (ICR), directed hydrogenation and allylic diazene rearrangement.

Heparin-Peptide Interactions, Jacqueline Anastasia Morris

Graduate Theses and Dissertations

Heparin is a polydispersed sulfated molecule that is part of the family called glycosaminoglycans found in the extracellular matrix and cell surfaces. This molecule is extremely important for the activation of proteins and protein-receptor interactions that are responsible for downstream cell signaling pathways. Heparin has been isolated from porcine intestine and used as an anticoagulant for the prevention of embolisms, heart thrombosis, and clotting during heart surgeries. This so-called miracle drug was in use until 2008, when isolated batches were found to be contaminated with other glycosaminoglycans similar to heparin. From 2008, there has been a dire need for a …

Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce

Civil and Environmental Engineering Faculty Publications and Presentations

New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low volatility species, from diameters ∼ 1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids …

Binding Properties Of Large Antiviral Polyamides (Pa1 And Pa25) And Natural Product Derivatives As Inhibitors Of Serine Hydrolases, Elena Vasilieva

Dissertations

Polyamides are a class of DNA minor groove binders that were developed from the natural product Distamycin A. PA25 (20-ring PA) showed better activity (3-fold) in the elimination of HPV16 episomes than PA1 (14-ring PA). Binding studies of PA1 and PA25 were performed in the long control region of HPV16 (7348-122 bp). PA1 showed similar binding affinity to perfect match and single mismatch binding sites. PA1 bound to double, triple, and quadruple mismatch sites with lower affinity. PA25 bound with similar binding affinity to perfect through triple mismatch binding sites. PA25 bound quadruple mismatch sites and nonspecifically. Therefore, it was …

Fulleretic Well-Defined Scaffolds: Donor–Fullerene Alignment Through Metal Coordination And Its Effect On Photophysics, Derek E. Williams, Ekaterina A. Dolgopolova, Danielle C. Godfrey, Evgeniya D. Ermolaeva, Perry J. Pellechia Dr., Andrew B. Greytak Prof. Dr., Mark Smith Dr., Stanislav M. Avdoshenko, Dr., Alexey A. Popov Dr., Natalia B. Shustova Prof. Dr.

Faculty Publications

Herein, we report the first example of a crystalline metal–donor–fullerene framework, in which control of the donor–fullerene mutual orientation was achieved through chemical bond formation, in particular, by metal coordination. The 13C cross-polarization magic-angle spinning NMR spectroscopy, X-ray diffraction, and time-resolved fluorescence spectroscopy were performed for comprehensive structural analysis and energy-transfer (ET) studies of the fulleretic donor–acceptor scaffold. Furthermore, in combination with photoluminescence measurements, the theoretical calculations of the spectral overlap function, Förster radius, excitation energies, and band structure were employed to elucidate the photophysical and ET processes in the prepared fulleretic material. We envision that the well-defined fulleretic donor–acceptor …

Mida Boronates Are Hydrolysed Fast And Slow By Two Different Mechanisms, Jorge A. Gonzalez, O. Maduka Ogba, Gregory F. Morehouse, Nicholas Rosson, Kendall N. Houk, Andrew G. Leach, Paul H.-Y. Cheong, Martin D. Burke, Guy C. Lloyd-Jones

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

MIDA boronates (N-methylimidodiacetic boronic acid esters) serve as an increasingly general platform for building-block-based small molecule construction, largely due to the dramatic and general rate differences with which they are hydrolysed under various basic conditions. Yet the mechanistic underpinnings of these rate differences have remained unclear, hindering efforts to address current limitations of this chemistry. Here we show that there are two distinct mechanisms for this hydrolysis: one is base-mediated and the other neutral. The former can proceed more than three orders of magnitude faster, and involves rate-limiting attack at a MIDA carbonyl carbon by hydroxide. The alternative ‘neutral’ hydrolysis …

C60 And Sc3N@C80(Tmb-Ppo) Derivatives As Constituents Of Singlet Oxygen Generating, Thiol-Ene Polymer Nanocomposites, Emily M. Barker, Ashli R. Toles, Kyle A. Guess, J. Paige Buchanan

Faculty Publications

Numerous functionalization methods have been employed to increase the solubility, and therefore, the processability of fullerenes in composite structures, and of these radical addition reactions continue to be an important methodology. C₆₀ and Sc₃N@C₈₀ derivatives were prepared via radical addition of the photodecomposition products from the commercial photoinitiator TMB-PPO, yielding C₆₀(TMB-PPO)₅ and Sc₃N@C₈₀(TMB-PPO)₃ as preferred soluble derivatives obtained in high yields. Characterization of the mixture of isomers using standard techniques suggests an overall 1PPO:6TMB ratio of addends, reflecting the increased reactivity of the carbon radical. Although, a higher …

Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko

Dissertations and Theses

Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …

Effects Of Angular Deformation On The Energetics Of The Sn2 Reaction, Vincent De Paul Nzuwah-Nziko, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Quantum calculations are applied to a number of model SN2 reactions. The halides F-, Cl-, and Br- were allowed to attack the central C atom of a set of CH2RI molecules, with R= H, CH3, CH=CH2, C≡CH, and C≡N. For each system the X∙∙C∙∙I angle was distorted in set increments from the optimized value, and the activation energy computed for each angle. The energy of the transition state rose in conjunction with this deformation. However, the distortion energy of the initial X-∙∙CH2RI reaction complex was similar in magnitude. As a result, the activation energy of the reaction was quite insensitive …

Interpretation Of Spectroscopic Markers Of Hydrogen Bonds, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Quantum calculations are used to examine whether a AH∙∙D H-bond is unambiguously verified by a downfield shift of the bridging proton’s NMR signal or a red (or blue) shift of the AH stretching frequency in the IR spectrum. It is found that such IR band shifts will occur even if the two groups experience weak or no attractive force, or if they are drawn in so close together that their interaction is heavily repulsive. The mere presence of a proton-acceptor molecule can affect the chemical shielding of a position occupied by a proton-donor by virtue of its electron density, even …

58th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 58th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Breckenridge, Colorado, July 17-21, 2016.

Synthesis And Structure Activity Relationship Of Novel Small Molecules As Inhibitors Of Plasminogen Activator Inhibitor-1, Karl Michael Upman

Master's Theses and Doctoral Dissertations

Plasminogen activator inhibitor type-1 (PAI-1) is a member of the serine protease inhibitor (serpin) family. PAI-1 is involved in the regulation of fibrinolysis, which is the breakdown of blood clots. PAI-1 inhibits serine proteases tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), which are key factors in fibrinolysis. Excess levels of PAI-1 have also been shown to increase the risk of diabetes, stroke, and atherosclerosis, as well as tumor development. Previous attempts at synthesizing a practical drug for the regulation of PAI-1 have not been successful; therefore, it has been the purpose of this study to further advance progress …

Diastereoselective Aza-Cope Rearrangement-Mannich Cyclizations Of Conformationally Mobile Iminium Cations, Joshua Hunt

Master's Theses and Doctoral Dissertations

We have developed a Lewis-acid catalyzed, diastereoselective aza-Cope rearrangement— Mannich cyclization (ACM) to form acyl pyrrolidines from conformationally mobile substrates. Earlier studies from our lab have shown that substituted acyl pyrrolidines can be synthesized with diastereoselectivity of 50:1 trans to cis, and that unsubstituted pyrrolidines can be synthesized with 13:1 enantioselectivity. This study attempted to observe the stereochemical outcomes of the ACM for disubstituted pyrrolidine systems using oxazolidine starting materials. A proof of concept dimethyl-substituted oxazolidine was subjected to ACM conditions, producing the pyrrolidine with good yields. However, when methyl-phenyl substituted oxazolidine was subjected to ACM conditions, undesired byproduct …

Serendipitous Discovery Of A New Method For The Catalytic Synthesis Of Indole-Fused Benzazepanes, Edward Gluzman, Paul A. Vadola

DePaul Discoveries

We report here on our investigations into the application of 1,5-hydride transfer cyclization mechanisms to the synthesis of 2,3-disubstituted benzofurans and indoles. We found that PtI₄ in MeCN at 120 ºC was indeed capable of activating the alkyne, however, the expected 2,3-disubstituted indole product was not observed. Instead we isolated an indolyl-3-benzazepane via an unexpected intramolecular Steven’s rearrangement/ring expansion. While this transformation has been previously reported our method may prove to have increased substrate scope and more practical reaction conditions. Further studies are underway to optimize the reaction conditions and to fully explore the scope and mechanism of the …

Interactions Between Temozolomide And Quercetin, Okuma Emile Kasende, Vincent De Paul Nzuwah-Nziko, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Temozolomide and quercetin are both molecules with important pharmaceutical activity, whose effects can mutually enhance one another when clinically applied simultaneously. Quantum chemical calculations are used to examine how the two molecules might interact with one another. The most stabilizing force arises when the aromatic systems of the two molecules are arranged parallel to one another. These stacked configurations are reinforced by H-bonds, but geometries containing only H-bonds, without the aromatic stacking, are much less stable, even if the H-bonds are short and strong. Comparison between B3LYP and B3LYP-D binding energies allows an evaluation of dispersion energy, which is found …

Layered Xerogel Films Incorporating Monolayer Protected Cluster Networks On Platinum Black Modified Electrodes For Enhanced Sensitivity In 1st Generation Uric Acid Biosensing, Mulugeta B. Wayu, Michael J. Pannell, Michael C. Leopold

Chemistry Faculty Publications

Amperometric uric acid (UA) biosensing schemes incorporating networks of alkanethiolate‐protected gold nanoparticles, monolayer protected clusters (MPCs), and platinum black (Pt‐B) electrode modification through the layer‐by‐layer construction of xerogels are investigated. MPC doping and Pt‐B augmentation are implemented within hydroxymethyltriethoxysilane xerogel bilayers at platinum electrodes. The first xerogel adlayer is doped with an MPC network and houses uricase for the enzymatic reaction required for first‐generation schemes. Polyluminol–aniline and polyurethane are used as selective/stabilizing interfacial layers. The sensing performance with and without Pt‐B and/or MPC doping is assessed by amperometry with standardized UA injections. The use of each individual material results in …

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

Multiplexed Detection Of Double-Stranded Pathogenic Dna With Engineered Zinc Finger Proteins, Juhwa Kim

Masters Theses & Specialist Projects

The development of a new technology for the detection of doublestranded (ds) DNA enables multiple biomedical applications including identifying multiple pathogens simultaneously. We previously employed colorimetric SEquence-Enabled Reassembly with TEM-1 β-lacatamase (SEER-LAC) to detect specific bacterial DNA sequence. SEER-Lac consists of the two inactive β-lactamase fragments which of each attached to a zinc finger protein (ZFP) would reassemble into an active full-length enzyme upon ZFPs binding to its target DNA. Here, we engineered two pairs of ZFPs which of each recognizes shiga toxin in E. coli O157 and staphylococcal enterotoxin B in Staphylococus Aureus, respectively. Biotin was simply conjugated to …

Development Of Organocatalytic Reactions For The Assembly Of Complex Molecules, Chenguang Yu

Chemistry and Chemical Biology ETDs

Development of efficient organocatalytic reactions for the facile assembly of synthetically and medicinally useful molecules is an important task in modern organic synthesis. Towards this end, my Ph. D. study focuses on the development of novel organocatalytic reactions for the construction of structurally diverse molecular architectures. A chiral bifunctional amine thiourea as promoter has been developed as an efficient solution to a long standing challenging issue in atropo-enantioselective transesterification of the Bringmann lactones. This organocatalytic approach delivers the first highly enantioselective, high yielding dynamic kinetic resolution process for the preparation of axially chiral biaryl compounds with a broad substrate scope …

Electrogenerated Chemiluminescence Of Luminophores And Enhancement With Melatonin, Sarah Michelle Roughton

Graduate Theses/Dissertations

The photoluminescent (PL), electrochemical, and electrogenerated chemiluminescent (ECL) properties of 1,5-I-Aedans (N-(iodoacetylaminotheyl)-1-naphthylamine-5-sulfonic acid) in aqueous buffered (KH2PO4) and 50:50 (v/v) acetonitrile:KH2PO4 solutions were obtained. Tri-n-propylamine (TPrA) was used as the oxidative-reductive coreactant. The PL efficiencies (em) were 1.83 in KH2PO4 and 4.81 in mixed solvent compared to Ru(bpy)32+ standard solutions (em = 1.0). 1,5-I-Aedans displayed quasi-reversible oxidative electrochemistry in aqueous solutions and irreversible to quasi-reversible oxidation in mixed solvent. ECL efficiencies (ecl) were obtained by comparison to a Ru(bpy)32+/TPrA (bpy = 2,2'-bipyridine) standard (ecl = 1) and were higher in KH2PO4 (ecl = 6.8 x 10-4) than in the mixed …

Student Identification Of Problem Topics In General Chemistry, Michelle Denyse Hilda Herridge

Graduate Theses/Dissertations

Eliciting students' beliefs regarding the difficulty of subject matter is important since self-efficacy often determines study habits. The goal of this research was to investigate students' perceptions about the relative difficulty of topics taught in tertiary-level introductory chemistry courses. As a proof of concept, I created a survey composed of topics adapted from the South Carolina high school chemistry standards. This survey was piloted at Clemson University, where general chemistry students at the end of their first-semester were asked to rank the topics by perceived level of difficulty. Based on the pilot data analysis the survey was revised, adapted and, …

Synthetic Investigation On The Biomimetic Metal-Catalyzed Sulfoxidations And Photochemical Generation Of A Highly Reactive Ruthenium(V)-Oxo Porphyrin, Weilong Luo

Masters Theses & Specialist Projects

Catalytic oxidation plays a crucial role in current chemical and pharmaceutical industries which is also a leading technology for green chemical processes. In Nature, the ubiquitous cytochrome P450 enzymes can catalyze a wide variety of oxidation reactions with high efficiency and selectivity. Many transition metal catalysts are designed as the biomimetic model of cytochrome P450 enzymes. In this work, series of metalloporphyrins and metallocorroles have been successfully synthesized to investigate and develop catalytic selective oxidation of sulfides to sulfoxides.

Manganese(III) porphyrin complexes (2) and manganese(III) corrole complexes (6) with iodobenzene diacetate [PhI(OAc)2] as a mild oxygen source exhibited remarkable catalytic …

Molecular Structure And Exciton Dynamics In Organic Conjugated Polymers, Alan K. Thomas

Chemistry and Chemical Biology ETDs

Intermolecular electronic interactions, dipole coupling and orbital overlap, caused by π-π stacking in organic conjugated polymers lead to unique structures and properties that can be harnessed for optoelectronic applications. These interactions define structure-function relationships in amorphous and aggregated forms of polymers in the solid state and determine their efficiencies and functionality in electronic devices, from transistors to solar cells. Organic polymer electronic device performance depends critically upon electronic coupling between monomer units --mediated by conformation and packing characteristics -- that dictates electronic properties like conductivity and capacitance as well as electronic processes, such as charge carrier generation and transport. This …

Principles Of Chemistry I (Savannah State University), Cecil Jones, Adegboye Adeyemo, Pascal Binda

Chemistry Grants Collections

This Grants Collection for Principles of Chemistry I was created under a Round Four ALG Textbook Transformation Grant. It contains materials used within the implementation of OpenStax Chemistry.

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

Development Of Oligo(P-Phenylene Ehynylene)(Ope) Applications Against Chemical And Biological Threats, Suhyun Yoon

Chemistry and Chemical Biology ETDs

Four new applications of oligo-phenylene ethynylene (OPE) and poly-PE (PPE) compounds for detection and destruction of biological and chemical threats have been investigated. Mixed surfaces composed of PPEs and a thermoswitchable polymer were created, and were shown to be able to capture, kill, and reversibly release pathogenic bacteria. In order to develop fluorescent sensors for CW agents, the spectral changes of OPEs with surfactants and malathion (a simulant for nerve agents) were measured. Formation of OPE-dimers in the presence of surfactants can cause fluorescence enhancement (turn-on) or quenching (turn-off). Among six positive and negative OPEs, only OPEs with ethyl ester …

Studies Toward Yaku'amide A And Synthesis And Applications Of Bulky Α,Β-Dehydroamino Acids, Jintao Jiang

Theses and Dissertations

Yaku'amide A shows a unique inhibitory profile against a series of 39 human cancer cell lines (JFCR39). In our efforts to synthesize yaku'amide A, we have optimized our regioselective base-free aminohydroxylation method with a series of nitrogen sources, developed a chiral reagent-mediated aminohydroxylation strategy and chemoselective deprotections of the resulting aminohydroxylation product, and explored a stereospecific E2 dehydration and O-N acyl transfer sequence. In addition, we have prepared the right-hand tetrapeptide and the NTA subunit. For our bulky α,β-dehydroamino acids project, we have developed strategies to incorporate α,β-dehydroamino acids such as ΔVal and ΔEnv into small synthetic peptides via Solid …

Gas Phase Structure Characterization Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Anupriya Anupriya

Theses and Dissertations

This dissertation investigates Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) based techniques to study the impact of molecular structure on conformation and binding energetics. A novel method to determine collison cross sectional areas using FTICR (CRAFTI), initially developed by the Dearden lab, was applied to study the conformations of molecular systems with unique structural attributes in an attempt to explore the molecular range of CRAFTI. The systems chosen for CRAFTI studies include crown-ether alkylammonium complexes and biogenic amino acids. The results were found to be consistent with expected behavior, and strongly correlated with experimental measurements made using ion mobility …

Resonance Raman Studies Of Oxygenated Forms Of Myoglobin And Cyp2b4 And Their Mutants, Ying Wang

Dissertations (1934 -)

Important oxidative heme enzymes use hydrogen peroxide or activate molecular oxygen to generate highly reactive peroxo-, hydroperoxo- and feryl intermediates resulting from heterolytic O-O bond cleavage. Members of the cytochrome P450 superfamily catalyze difficult chemical transformations, including hydroxylations and C-C bond cleavage reactions. In mammals, these enzymes function to reliably produce important steroids with the required high degree of structural precision. On the other hand, certain other mammalian P450s serve a different role, efficiently metabolizing xenobiotics, including pharmaceuticals and environmental pollutants. Though so important, the precise mechanisms involved in such transformations are incompletely understood, because of difficulties in structurally characterizing …

Role Of Ros And Rns Sources In Physiological And Pathological Conditions, Sergio Di Meo, Tanea Reed, Paola Venditti, Victor Manuel Victor

EKU Faculty and Staff Scholarship

There is significant evidence that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. Mitochondria have been thought to both play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including stimulation of opening of permeability transition pores. Until recently, the functional significance of ROS sources different from mitochondria has received lesser attention. However, the most recent data, besides confirming …