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Full-Text Articles in Physical Sciences and Mathematics

Fluoroethoxy-1,4-Diphenethylpiperidine And Piperazine Derivatives: Potent And Selective Inhibitors Of [3H]Dopamine Uptake At The Vesicular Monoamine Transporter-2, Emily R. Hankosky, Shyam R. Joolakanti, Justin R. Nickell, Venumadhav Janganati, Linda P. Dwoskin, Peter A. Crooks Dec 2017

Fluoroethoxy-1,4-Diphenethylpiperidine And Piperazine Derivatives: Potent And Selective Inhibitors Of [3H]Dopamine Uptake At The Vesicular Monoamine Transporter-2, Emily R. Hankosky, Shyam R. Joolakanti, Justin R. Nickell, Venumadhav Janganati, Linda P. Dwoskin, Peter A. Crooks

Pharmaceutical Sciences Faculty Publications

A small library of fluoroethoxy-1,4-diphenethyl piperidine and fluoroethoxy-1,4-diphenethyl piperazine derivatives were designed, synthesized and evaluated for their ability to inhibit [3H]dopamine (DA) uptake at the vesicular monoamine transporter-2 (VMAT2) and dopamine transporter (DAT), [3H]serotonin (5-HT) uptake at the serotonin transporter (SERT), and [3H]dofetilide binding at the human-ether-a-go-go-related gene (hERG) channel. The majority of the compounds exhibited potent inhibition of [3H]DA uptake at VMAT2, with Ki values in the nanomolar range (Ki = 0.014–0.073 μM). Compound 15d exhibited the highest affinity (Ki = 0.014 μM) at VMAT2, and had 160-, 5-, …


Abiotic- And Biotic-Formation Of Manganese Oxides And Their Fate In Environmental Systems, Haesung Jung Dec 2017

Abiotic- And Biotic-Formation Of Manganese Oxides And Their Fate In Environmental Systems, Haesung Jung

McKelvey School of Engineering Theses & Dissertations

Manganese (hydr)oxide (Mn (hydr)oxide) minerals are ubiquitous in aquatic and terrestrial environments. These minerals have high surface areas and are highly sorptive and redox active. From decades of accumulated knowledge about natural redox cycling, we have found that Mn (hydr)oxides play critical roles as electron donors and acceptors in elemental geochemical cycling and biological metabolisms in nature. Thus, Mn (hydr)oxides have garnered increasing interest to understand natural systems. Considering the variety of redox reactions with Mn (hydr)oxides in nature, it is also expected that there should be diverse pathways to form Mn (hydr)oxides through abiotic and biotic processes. Previous studies …


Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov Dec 2017

Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov

Michigan Tech Publications

Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed …


Oxidation Of Dibenzothiophene To Dibenzothiophene-Sufone Using A Molybdenum (Vi) Oxide Catalyst: A Kinetic Study Testing Solvent Dependency And Mole Ratio Efficiency, Tomas Trevino Jr. Dec 2017

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sufone Using A Molybdenum (Vi) Oxide Catalyst: A Kinetic Study Testing Solvent Dependency And Mole Ratio Efficiency, Tomas Trevino Jr.

Theses and Dissertations

Oxidative desulfurization (ODS) is currently a solution to hydrodesulphurization. Currently, industrial usage of hydrodesulphurization (HDS) is the common source for petroleum purification. Unfortunately, HDS comes with environmental and economical ramifications. Due to the problems and potential hazards being presented with HDS, ODS has become a topic of interest in research development. A kinetic study using molybdenum (VI) oxide as a catalyst was used in oxidative desulfurization. Factors such as mole ratio and solvent dependency were tested for efficiency. As activation energy was calculated to show maximum efficiency with respect to temperature and concentration. Gas Chromatography, FT-IR, and Mass Spectroscopy were …


Remediation Of Trivalent And Hexavalent Chromium Ions From Aqueous Solutions Using Titanium Dioxide Polymorphs, Yvette Cantu Dec 2017

Remediation Of Trivalent And Hexavalent Chromium Ions From Aqueous Solutions Using Titanium Dioxide Polymorphs, Yvette Cantu

Theses and Dissertations

Three titanium dioxide (TiO2) polymorphs were synthesized and used for the removal of chromium (III) and chromium (VI) from aqueous solutions. Various solution parameters were studied to determine the effects of pH, temperature, time, possible interfering ions, and capacities on the binding of Cr(III) and Cr(VI) to all three polymorphs. pH assays determined the optimum pH for the binding of both Cr(III) and Cr(VI) to each polymorph. Adsorption isotherms determined that the adsorption of Cr(III) was non-spontaneous for the three polymorphs with ΔG values ranging from 6.03 to 12.89 kJ/mol. Furthermore, the binding of Cr(VI) to anatase was also non-spontaneous …


Remediation Of Lead And Copper Ions From Water Solutions Using Transition Metal Sulfides, Jesus M. Cantu Jr. Dec 2017

Remediation Of Lead And Copper Ions From Water Solutions Using Transition Metal Sulfides, Jesus M. Cantu Jr.

Theses and Dissertations

Heavy metal contamination in water solutions has been a major concern since many transition metals don’t play a role in any biological function and are actually detrimental to human health. There have been several techniques that have been implemented for the remediation of heavy metal contaminants. For this project, three metal sulfides—Fe7S8, ZnS, TiS 2—were synthesized and studied for their capabilities to remove Pb(II) and Cu(II) from water solutions. Several parameters were investigated to determine the effects of pH, time, temperature, binding capacities, and interfering ions. The room temperature adsorption capacities ranged 6.23–333.3 mg/g for Pb(II) and 1.31–250 mg/g for …


Thermochemistry Of Fluorinated Aldehydes And Corresponding Radicals;Thermochemistry And Kinetics Of Diethyl Ether And Ethyl Oxirane Relative To Reactions Under Atmospheric And Combustion Conditions, Douglas Lee Purnell Jr. Oct 2017

Thermochemistry Of Fluorinated Aldehydes And Corresponding Radicals;Thermochemistry And Kinetics Of Diethyl Ether And Ethyl Oxirane Relative To Reactions Under Atmospheric And Combustion Conditions, Douglas Lee Purnell Jr.

Dissertations

Fundamental thermochemical properties including enthalpies (ΔH°f 298), entropies (S°(T)), heat capacities (Cp(T)), and bond dissociation energies (BDEs) for several common and complex hydrocarbon fuel species are determined using computational chemical methods. ΔH°f 298 values are calculated using isodesmic reactions with the CBS-APNO, CBS-4M, CBS-QB3, G2, G3, G4, Weizmann-1 (W1U) and M06-2X, ωB97X, B3-LYP with basis set 6-31G+ (d,p) and 6-31G++(d,p) calculation methods. Structures, moments of inertia, vibrational frequencies, and internal rotor potentials are calculated for contributions to entropies and heat capacities. Kinetic rate parameters are calculated for hydrogen abstraction and …


Analyzing The Kinetics Of A Bromophenol Blue Fading Reaction In Basic Conditions For An Undergraduate Lab, Zeljka Popovic Apr 2017

Analyzing The Kinetics Of A Bromophenol Blue Fading Reaction In Basic Conditions For An Undergraduate Lab, Zeljka Popovic

Georgia College Student Research Events

Bromophenol blue is a common pH indicator and dye used in many different industries. Once a solution of bromophenol blue is placed in a concentrated basic solution, the color fades from a blue/violet color to clear solution with a pH of 4.6 or greater. The rate law of the reaction is analyzed through the use of a small footprint visible-near-infrared spectrometer (Vis-NIR) with a diode array detector. An absorbance wavelength of 590 nm as a function of time was collected using Ocean Optics OceanView software. The results contained in the data collection file are exported to a spreadsheet for further …


Synthesis, Kinetic And Catalytic Studies Of Manganese Complexes With Corrole And Porphyrin Ligands, Haleh Jeddi Apr 2017

Synthesis, Kinetic And Catalytic Studies Of Manganese Complexes With Corrole And Porphyrin Ligands, Haleh Jeddi

Masters Theses & Specialist Projects

High-valent transition metal-oxo intermediates play a significant role in the catalytic cycle of the ubiquitous cytochrome P450 enzymes and in biomimetic catalytic systems. In this work, manganese(III) porphyrin and corrole systems (2) were synthesized and characterized by UV-vis absorbance and 1H-NMR, matching literaturereported spectroscopic data. Manganese(V)-oxo corroles (3) and a manganese(IV)-oxo porphyrin (4) were successfully generated by chemical oxidation using mchloroperoxybenzoic acid (m-CPBA), and their oxidation reactions with organic reductants were comparatively investigated. Results from single-turnover kinetic studies indicate that in the tris(pentafluorophenyl)corrole system (3a), the active oxidizing intermediate differs in different solvents. The active oxidizing intermediate in acetonitrile is …


Theoretical Study Of Ozone Forming Recombination Reaction And Anomalous Isotope Effect Associated With It, Alexander Teplukhin Apr 2017

Theoretical Study Of Ozone Forming Recombination Reaction And Anomalous Isotope Effect Associated With It, Alexander Teplukhin

Dissertations (1934 -)

The ozone forming recombination reaction stands out among many chemical processes that take place in the atmosphere. This reaction is responsible for the reconstruction of ozone layer, which protects life on Earth from harmful ultra-violate radiation and is a source of so-called anomalous isotope effect in ozone. The reaction was intensively studied, but at a very basic level. There were only couple of papers where the recombination rate coefficient was computed and found to roughly agree with the experimental data. In this dissertation, the recombination process in ozone is approached using new and efficient method, which includes several modern techniques. …


Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo Jan 2017

Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo

Turkish Journal of Chemistry

Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R$^{2}$ and low $\chi^{2}$ values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were 28.09 and 27.17 mg g$^{-1}$ for Pb(II) and for Cd(II), respectively. The pseudo-second order kinetic model explained the kinetic …