Chemistry Commons^™

Synthesis And Catalytic Evaluation Of Novel C-Alpha-Methyl-Beta-Proline Analogues, And Concise Synthetic Approach To Nh-Fmoc-S-Trityl-C-Alpha-Methyl Cysteine, Hari Kiran Kotapati

Dissertations

In the field of chemistry there is a growing demand for small molecule organocatalysts such as amino acids, more specifically proline and its analogues, which could catalyze various key chemical reactions in the synthesis of several biologically important molecules. Even though natural proline is reported to catalyze various chemical reactions, its use as organocatalyst is limited mainly due to the solubility issues in the reaction media and high catalyst loadings, which is not very ideal for bulk scale manufacturing. To address these limitations we planned to develop unnatural analogues of proline that could catalyze the reactions with lower catalyst loadings ...

Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency ...

Detection Of Tetracyclines In An Anaerobic Waste Digester Using Solid Phase Extraction And High-Performance Liquid Chromatography Mass Spectrometry, Courtney Cruse

Honors College Capstone Experience/Thesis Projects

Antibiotics are introduced to livestock to encourage growth and for the treatment of diseases. These antibiotics are not completely metabolized by swine, and thus these antibiotics are excreted with their waste. This poses a potential risk to human health as these antibiotics, a potential link to antibiotic resistant bacteria, then enter the surface water, ground water, and soil. In collaboration with the US Department of Agriculture (USDA) in Bowling Green, Kentucky, this research is concerned with analyzing the degradation of tetracyclines in swine waste from an anaerobic digester. Waste samples obtained from a digester and swine waste at the USDA ...

Cytotoxicity Of Platinum Anticancer Drugs In Mammalian Cell Lines Of Metastatic Cancer, Hosannah Evie

Honors College Capstone Experience/Thesis Projects

With the invention of advanced technology, focus has been put on understanding and looking for potential cures for many diseases, one of which is cancer. The difference in the leaving and non-leaving ligands of the FDA approved cancer drugs contributes to the differential cell specific cytotoxic effects. These drugs such as oxaliplatin approved for colorectal cancer, cisplatin approved for testicular cancer, and their analogs were used to treat different cancer cell lines in an MTT assay. This project aims to determine how changing the molecular shape of these compounds affects their uptake and toxicity into different cell lines. The assay ...

A Real Time Optical Biosensor Assay For Amoxicillin And Other Β-Lactams In Water Samples, Israel M. Scott, Lewis J. Kraft, Jonathan D. Parker, Kathryn Daniel, Sarah Kustick, Diana Kennen, Jonathan Mcmurry

Georgia Journal of Science

Antibiotic contamination of drinking water and sewage is a matter of environmental and public health concern. Traditionally, ELISA or HPLC methods have been used to detect and measure antibiotic contamination. By applying an optical biosensing method, biolayer inteferometry (BLI), we have developed a kinetic competition binding assay capable of quantitating less than 1ppm (~33 μM) amoxicillin. Similar to surface plasmon resonance, BLI senses changes that occur upon binding of one molecule to another near a surface to measure association and dissociation. Immobilized amoxicillin was used to screen for binding against an analyte solution of anti-amoxicillin equilibrated with amoxicillin-containing water samples ...

Structure Of Porphyrin Tpps4 And Its Interaction With Metal Ions As Elucidated By 1h Nmr And Uv-Visible Spectra, Zhiyan Song, Adegboye O. Adeyemo, Jannie Baker, Shakeya M. Taylor, Marcia L. Lightfoot

Georgia Journal of Science

Porphyrins are a group of tetrapyrrole pigments. Physical and chemical properties of porphyrins are often related to their compositions and structures. We conducted ¹H solution NMR and UV-visible spectral analysis to characterize the structural feature of a water-soluble, synthetic porphyrin i.e. tetrakis (p-sulfonatophenyl) porphyrin, TPPS₄, and its interaction with different metal ions in aqueous solutions. The results indicate that tetrapyrrole and tetraphenyl rings in TPPS₄ molecule form a co-planar electron conjugation system; transition-metal ions show stronger binding capacity than alkali and alkali-earth metal ions; the relative stabilities of TPPS₄-metal ion complexes can be well ...

Multi-Regression Prediction Of Metal Partition Coefficients Under Various Physical/Chemical Conditions Design Of Experiments As, Cr, Cu, Ni And Zn, Eid A. Alkhatib, Danielle Grunzke, Trey Chabot

Eid A. Alkhatib

The behavior of metals in surface water is complex and their partition coefficients can be impacted by many factors. Organic matter (OM) content in sediments, pH and salinity, are factors that may influence speciation and partitioning of metals. The difficulty in describing the impacts and relationships are that these processes are interconnected with no dominant associations among all. In this study, the partitioning of five metals (As, Cr, Cu, Ni and Zn) under different levels of salinity, pH, and OM content were investigated. A series of factorial design experiments are evaluated in which three levels of OM are tested each ...

Prediction Of Metal Remobilization From Sediments Under Various Physical/ Chemical Conditions “Design Of Experiments Cd, Co And Pb”, Eid A. Alkhatib, Trey Chabot, Danielle Grunzke

Eid A. Alkhatib

The metal partition coefficient Kd (L/kg) is the ratio of sorbed metal concentration on the solid phase m (mg/kg) to the dissolved metal concentration at equilibrium. The behavior of metals in surface water is complex and their partition coefficients can be impacted by many factors. Organic matter (OM) content in sediments, pH and salinity, are factors that may influence speciation and partitioning of metals. In this study, the partitioning coefficient of three metals (Cd, Co and Pb) under different levels of salinity, pH, and OM content were examined. A series of factorial experiments were evaluated in which three ...

Comparative Study Of The Tribological And Oxidative Properties Of Alpdmn Quasicrystals And Their Cubic Approximants, Chris Mancinelli, Jeff S. Ko, Cynthia J. Jenks, Patricia A. Thiel, Amy R. Ross, Thomas A. Lograsso, Andrew J. Gellman

Thomas A. Lograsso

An experimental comparison has been made between the properties of the surfaces of an Al₇₀Pd₂₁Mn₉quasicrystal and its Al₄₈Pd₄₂Mn₁₀ approximant. The Al₇₀Pd₂₁Mn₉ sample was a single grain icosahedral quasicrystal cut to expose its five-fold symmetric (000001) surface. The approximant was polycrystalline β-phase Al₄₈Pd₄₂Mn₁₀, which has a CsCl-type cubic structure. Surfaces of both were prepared under ultra-high vacuum (UHV) conditions and then used for comparative measurements of their frictional properties and oxidation rates. Both materials are oxidized by reaction with O ...

Self-Organized Molecular Films With Long-Range Quasiperiodic Order, Vincent Fournée, Émilie Gaudry, Julian Ledieu, Marie-Cécile De Weerd, Dongmei Wu, Thomas A. Lograsso

Thomas A. Lograsso

Self-organized molecular films with long-range quasiperiodic order have been grown by using the complex potential energy landscape of quasicrystalline surfaces as templates. The long-range order arises from a specific subset of quasilattice sites acting as preferred adsorption sites for the molecules, thus enforcing a quasiperiodic structure in the film. These adsorption sites exhibit a local 5-fold symmetry resulting from the cut by the surface plane through the cluster units identified in the bulk solid. Symmetry matching between the C60 fullerene and the substrate leads to a preferred adsorption configuration of the molecules with a pentagonal face down, a feature unique ...

Catalytic Conversion Reactions In Nanoporous Systems With Concentration-Dependent Selectivity: Statistical Mechanical Modeling, Andrés García, Jing Wang, Theresa L. Windus, Aaron D. Sadow, James W. Evans

Theresa Windus

Statistical mechanical modeling is developed to describe a catalytic conversion reaction A→Bc or Bt with concentration-dependent selectivity of the products, Bc or Bt, where reaction occurs inside catalytic particles traversed by narrow linear nanopores. The associated restricted diffusive transport, which in the extreme case is described by single-file diffusion, naturally induces strong concentration gradients. Furthermore, by comparing kinetic Monte Carlo simulation results with analytic treatments, selectivity is shown to be impacted by strong spatial correlations induced by restricted diffusivity in the presence of reaction and also by a subtle clustering of reactants, A.

Preliminary Structural Studies Of The Transcriptional Regulator Cmer From Campylobacter Jejuni, Chih-Chia Su, Feng Shi, Ruoyu Gu, Ming Li, Gerry Mcdermott, Edward Yu, Qijing Zhang

Qijing Zhang

In Campylobacter jejuni, a Gram-negative bacterial pathogen causing gastroenteritis in humans, the CmeR regulatory protein controls transcription of the multidrug transporter gene operon cmeABC. CmeR belongs to the TetR family of transcriptional regulators. The 210-residue CmeR consists of two functional motifs: an N-terminal DNA-binding domain and a C-terminal ligand-binding domain. It is predicted that the DNA-binding domain interacts directly with target promoters, while the C-terminal motif interacts with inducing ligands (such as bile salts). As an initial step towards confirming this structural model, recombinant CmeR protein containing a 6×His tag at the N-terminus was crystallized. Crystals of ligand-free CmeR ...

Characterization And Inhibition Of A Class Ii Diterpene Cyclase From Mycobacterium Tuberculosis: Implications For Tuberculosis, Francis M. Mann, Sladjana Prisic, Huayou Hu, Meimei Xu, Robert M. Coates, Reuben J. Peters

Reuben J. Peters

Mycobacterium tuberculosis remains a widespread and devastating human pathogen, whose ability to infiltrate macrophage host cells from the human immune system is an active area of investigation. We have recently reported the discovery of a novel diterpene from M. tuberculosis, edaxadiene, whose ability to arrest phagosomal maturation in isolation presumably contributes to this critical process in M. tuberculosis infections. (Mann, F. M., Xu, M., Chen, X., Fulton, D. B., Russell, D. G., and Peters, R. J. (2009) J. Am. Chem. Soc., in press). Here, we present characterization of the class II diterpene cyclase that catalyzes the committed step in edaxadiene ...

Chemistry 101-002 General Chemistry I Spring 2015, C. Britt Carlson

C. Britt Carlson

No abstract provided.

Chemistry 101-007 General Chemistry I Fall 2015, C. Britt Carlson

C. Britt Carlson

No abstract provided.

Chemistry 102-001 General Chemistry Ii Fall 2015, C. Britt Carlson

C. Britt Carlson

No abstract provided.

Investigation Of The Chemical Interface In The Soybean–Aphid And Rice–Bacteria Interactions Using Maldi-Mass Spectrometry Imaging, Adam T. Klein, Gargey B. Yagnik, Jessica D. Hohenstein, Zhiyuan Ji, Jiachen Zi, Malinda D. Reichert, Gustavo C. Macintosh, Bing Yang, Reuben J. Peters, Javier Vela, Young Jin Lee

Reuben J. Peters

Mass spectrometry imaging (MSI) is an emerging technology for high-resolution plant biology. It has been utilized to study plant–pest interactions, but limited to the surface interfaces. Here we expand the technology to explore the chemical interactions occurring inside the plant tissues. Two sample preparation methods, imprinting and fracturing, were developed and applied, for the first time, to visualize internal metabolites of leaves in matrix-assisted laser desorption ionization (MALDI)-MSI. This is also the first time nanoparticle-based ionization was implemented to ionize diterpenoid phytochemicals that were difficult to analyze with traditional organic matrices. The interactions between rice–bacterium and soybean ...

Calculations Of The Binding Affinities Of Protein-Protein Complexes With The Fast Multipole Method, Bongkeun Kim, Jiming Song, Xueyu Song

Jiming Song

In this paper, we used a coarse-grained model at the residue level to calculate the binding free energies of three protein-protein complexes. General formulations to calculate the electrostatic binding free energy and the van der Waals free energy are presented by solving linearized Poisson–Boltzmann equations using the boundary element method in combination with the fast multipole method. The residue level model with the fast multipole method allows us to efficiently investigate how the mutations on the active site of the protein-protein interface affect the changes in binding affinities of protein complexes. Good correlations between the calculated results and the ...

Tin Dioxide-Carbon Heterostructures Applied To Gas Sensing: Structure-Dependent Properties And General Sensing Mechanism, Catherine Marichy, Patricia A. Russo, Mariangela Latino, Jean-Philippe Tessonnier, Marc-Georg Wilinger, Nicola Donato, Giovanni Neri, Nicola Pinna

Jean-Philippe Tessonnier

Carbon materials such as carbon nanotubes (CNTs), graphene, and reduced graphene oxide (RGO) exhibit unique electrical properties, which are also influenced by the surrounding atmosphere. They are therefore promising sensing materials. Despite the existence of studies reporting the gas-sensing properties of metal oxide (MOx) coated nanostructured carbon, an incomplete understanding of their sensing mechanism remains. Here we report a systematic study on the preparation, characterization, and sensing properties of CNT and RGO composites with SnO2 coating. Atomic layer deposition (ALD) was applied to the conformal coating of the inner and outer walls of CNTs with thin films of SnO2 of ...

Evolution Of Cu2o Morphology During Copper Corrosion In The Presence Of Gamma-Radiation, Arielle M. Jean

Electronic Thesis and Dissertation Repository

In this work, experiments were carried out in order to develop a mechanistic understanding of the corrosion of copper metal in limited water volumes under gamma-radiation. When exposed to gamma-radiation, water decomposes into chemically reactive oxidizing and reducing species. Under a continuous radiation flux, the concentrations of the radiolytically produced oxidants eventually reach a pseudo-steady state that can influence the corrosion kinetics of metallic surfaces.

The evolution of the surface morphology during water droplet corrosion of copper in the presence of gamma-radiation was investigated as a function of irradiation time and pH. The oxide growth kinetics were studied by measuring ...