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Claire Vieille - One of the best experts on this subject based on the ideXlab platform.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
Karla I Ziegelmannfjeld - One of the best experts on this subject based on the ideXlab platform.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
Paitoon Tontiwachwuthikul - One of the best experts on this subject based on the ideXlab platform.
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synthesis of new amines for enhanced carbon dioxide co2 capture performance the effect of chemical structure on equilibrium solubility cyclic capacity kinetics of absorption and regeneration and heats of absorption and regeneration
Separation and Purification Technology, 2016Co-Authors: Sudkanueng Singto, Teeradet Supap, Supawan Tantayanon, Mohammed J Almarri, Paitoon Tontiwachwuthikul, Abdelbaki BenamorAbstract:Abstract This work focused on the synthesis of new tertiary amines by varying the alkyl chain length with/without hydroxyl group in the structure. The effect of chemical structure of newly synthesized tertiary amines; 4-(dimethylamino)-2-Butanol (DMAB), 4-(dipropylamino)-2-Butanol (DPAB), 4-(dibutylamino)-2-Butanol (DBAB), 4-((2-hydroxyethyl)(methyl)amino)-2-Butanol (HEMAB) and 4-((2-hydroxyethyl)(ethyl)amino)-2-Butanol (HEEAB) were evaluated based on CO 2 equilibrium solubility and cyclic capacity, as well as rates and heats of CO 2 absorption and regeneration. The results showed that three amines (i.e. DMAB, HEMAB and HEEAB) had the highest CO 2 absorption capacity (0.88, 0.44 and 0.68 mol CO 2 /mol amine at 313 K temperature and 15 kPa CO 2 partial pressure), and cyclic capacity (0.52, 0.26 and 0.40 at 313–353 K temperature range, 15 kPa CO 2 partial pressure). These amines also had fast CO 2 absorption rate (0.082, 0.111 and 0.142 mol CO 2 /min) and CO 2 regeneration rate (0.512, 0.452 and 0.295 mol CO 2 /min) while maintaining low heat of CO 2 absorption (−34.17, −56.21 and −69.79 kJ/mol CO 2 ) and heat input of CO 2 regeneration (39.73, 60.48 and 72.44 kJ/mol CO 2 ). Based on these results, DMAB, HEMAB, and HEEAB can be considered to be promising amine components for blending for a post combustion CO 2 capture process.
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co2 absorption kinetics of 4 diethylamine 2 Butanol solvent using stopped flow technique
Separation and Purification Technology, 2014Co-Authors: Teerawat Sema, Paitoon Tontiwachwuthikul, Zhiwu Liang, Kaiyun Fu, Raphael Idem, Yanqing NaAbstract:Abstract In the present work, a stopped-flow apparatus was used to determine the CO 2 absorption kinetics of 4-diethylamine-2-Butanol (DEAB) in terms of observed pseudo-first-order rate constant ( k 0 ) and second order reaction rate constant ( k 2 ). The experiments were done using DEAB in the concentration range of 0.10–0.90 kmol/m 3 , and a temperature range of 293–313 K. The p K a of DEAB was also experimentally determined over a temperature range of 278–333 K. The Bronsted relationship between the reaction rate constant obtained from the stopped-flow apparatus and p K a obtained from experimental determination was then evaluated. The results showed that the Bronsted correlation could predict the absorption rate constant with an AAD of 8.6%, which is within an acceptable range of 10%. By comparing through different evaluation techniques such as k 2 , p K a and Δ r G m ° , it was observed that DEAB has faster reaction kinetics than those of conventional tertiary amines, namely, DEMEA, DMMEA and MDEA.
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mass transfer performance of co2 absorption into aqueous solutions of 4 diethylamino 2 Butanol monoethanolamine and n methyldiethanolamine
Industrial & Engineering Chemistry Research, 2012Co-Authors: Abdulaziz Naami, Raphael Idem, Teerawat Sema, Mohamed Edali, Paitoon TontiwachwuthikulAbstract:The mass transfer performance of the absorption of CO2 in an aqueous solution of monoethanolamine was evaluated experimentally in a lab-scale absorber packed with high efficiency DX structured packing and compared with that of methyldiethanolamine (MDEA) as well as that of a newly developed tertiary amino alcohol, 4-diethylamino-2-Butanol (DEAB). The absorption experiments were conducted at atmospheric pressure, using a feed gas mixture containing 14.9% CO2 and 85.1% nitrogen in an absorption column containing DX structured packing. The absorption performance was presented in terms of the CO2 removal efficiency, absorber height requirement, effective interfacial area for mass transfer, and overall mass-transfer coefficient (KGav). In particular, the effects of parameters such as inert gas flow rate and liquid flow rate were compared for both DEAB and MDEA. The results show that the DEAB has a much higher removal efficiency for CO2 along the height of the column than MDEA. Also, the KGav of DEAB was much h...
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solubility and diffusivity of n2o in aqueous 4 diethylamino 2 Butanol solutions for use in postcombustion co2 capture
Industrial & Engineering Chemistry Research, 2012Co-Authors: Teerawat Sema, Raphael Idem, Abdulaziz Naami, Mohamed Edali, Paitoon TontiwachwuthikulAbstract:In this work, the solubility and diffusivity of nitrous oxide (N2O) in aqueous 4-(diethylamino)-2-Butanol (DEAB) solutions were measured. Solubility was measured in a stirred cell reactor over the temperature range of 298–343 K and concentration range of 0.68–3.77 M. On the other hand, diffusivity was measured in a laminar jet absorber over the temperature range of 298–318 K and concentration range of 1.0–2.5 M. An attempt was made to correlate the solubility data with well-known models (semiempirical model, Redlich–Kister equation, and polynomial model). It was observed that only the polynomial model correlated the solubility of N2O in aqueous DEAB solution satisfactorily with an AAD of 0.1%. Similarly, an attempt was made to correlate the diffusivity data with well-known models (semiempirical model and modified Stokes–Einstein model). The semiempirical model provided better predicted N2O diffusivity data compared with the experimental data with an AAD of 3.4%. These data can then be used to determine th...
Michael H Abraham - One of the best experts on this subject based on the ideXlab platform.
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abraham model correlations for solute transfer into 2 methyl 2 Butanol based on measured activity coefficient and solubility data at 298 15 k
Journal of Molecular Liquids, 2019Co-Authors: Igor A Sedov, William E Acree, Timur M Salikov, Ellen Qian, Anisha Wadawadigi, Olivia Zha, Michael H AbrahamAbstract:Abstract Experimental infinite dilution activity coefficients, gas-to-liquid partition coefficients and mole fraction solubilities are reported for numerous liquid and solid organic compounds dissolved in 2-methyl-2-Butanol at 298.15 K. Experimental values were determined using headspace chromatographic and spectroscopic methods of analysis. Abraham model correlations were developed by combining our measured values with solubility data gathered from the published chemical literature. The mathematical correlations that we have developed described the measured partition coefficient and solubility data to within 0.14 log units (or less).
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enthalpy of solvation correlations for organic solutes and gases dissolved in 2 propanol 2 Butanol 2 methyl 1 propanol and ethanol
Thermochimica Acta, 2011Co-Authors: Timothy W Stephens, Nohelli E De La Rosa, Mariam Saifullah, Vicky Chou, Amanda N Quay, William E Acree, Michael H AbrahamAbstract:This article discusses the enthalpy of solvation correlations for organic solutes and gases dissolved in 2-propanol, 2-Butanol, 2-methyl-1-propanol and ethanol.
Robert S Phillips - One of the best experts on this subject based on the ideXlab platform.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
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a thermoanaerobacter ethanolicus secondary alcohol dehydrogenase mutant derivative highly active and stereoselective on phenylacetone and benzylacetone
Protein Engineering Design & Selection, 2007Co-Authors: Karla I Ziegelmannfjeld, Gregory J. Zeikus, Musa M Musa, Robert S Phillips, Claire VieilleAbstract:The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals containing secondary alcohol groups. TeSADH has no detectable activity on this alcohol, but it is highly active on 2-Butanol. The structural model we used to plan our mutagenesis strategy was based on the substrate's orientation in a horse liver alcohol dehydrogenase*p-bromobenzyl alcohol*NAD(+) ternary complex (PDB entry 1HLD). The W110A TeSADH mutant now uses (S)-1-phenyl-2-propanol, (S)-4-phenyl-2-Butanol and the corresponding ketones as substrates. W110A TeSADH's kinetic parameters on these substrates are in the same range as those of TeSADH on 2-Butanol, making W110A TeSADH an excellent catalyst. In particular, W110A TeSADH is twice as efficient on benzylacetone as TeSADH is on 2-Butanol, and it produces (S)-4-phenyl-2-Butanol from benzylacetone with an enantiomeric excess above 99%. W110A TeSADH is optimally active at 87.5 degrees C and remains highly thermostable. W110A TeSADH is active on aryl derivatives of phenylacetone and benzylacetone, making this enzyme a potentially useful catalyst for the chiral synthesis of aryl derivatives of alcohols. As a control in our engineering approach, we used the TbSADH*(S)-2-Butanol binary complex (PDB entry 1BXZ) as the template to model a mutation that would make TeSADH active on (S)-1-phenyl-2-propanol. Mutant Y267G TeSADH did not have the substrate specificity predicted in this modeling study. Our results suggest that (S)-2-Butanol's orientation in the TbSADH*(S)-2-Butanol binary complex does not reflect its orientation in the ternary enzyme-substrate-cofactor complex.
