The Experts below are selected from a list of 4206 Experts worldwide ranked by ideXlab platform
Thomas K Wood - One of the best experts on this subject based on the ideXlab platform.
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enantioconvergent production of r 1 phenyl 1 2 Ethanediol from styrene oxide by combining the solanum tuberosum and an evolved agrobacterium radiobacter ad1 epoxide hydrolases
Biotechnology and Bioengineering, 2006Co-Authors: Wilfred Chen, Thomas K WoodAbstract:Solubleepoxidehydrolase(EH)fromthepotato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA-I219F, were pur- ified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)-1-phenyl-1,2- Ethanediol, which is an important intermediate for pharmaceuticals. EchA-I219F has enhanced enantioselec- tivity (enantiomeric ratio of 91 based on products) for converting (R)-styrene oxide to (R)-1-phenyl-1,2-ethane- diol (2.0 � 0.2 mmol/min/mg), and the potato EH converts (S)-styrene oxide primarily to thesame enantiomer, (R)-1- phenyl-1,2-Ethanediol (22 � 1 mmol/min/mg), with an enantiomeric ratio of 40 � 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)-1-phenyl-1,2-Ethanediol at 4.7 � 0.7 mmol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid
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Enantioconvergent production of (R)‐1‐phenyl‐1,2‐Ethanediol from styrene oxide by combining the Solanum tuberosum and an evolved Agrobacterium radiobacter AD1 epoxide hydrolases
Biotechnology and bioengineering, 2006Co-Authors: Li Cao, Wilfred Chen, Jintae Lee, Thomas K WoodAbstract:Solubleepoxidehydrolase(EH)fromthepotato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA-I219F, were pur- ified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)-1-phenyl-1,2- Ethanediol, which is an important intermediate for pharmaceuticals. EchA-I219F has enhanced enantioselec- tivity (enantiomeric ratio of 91 based on products) for converting (R)-styrene oxide to (R)-1-phenyl-1,2-ethane- diol (2.0 � 0.2 mmol/min/mg), and the potato EH converts (S)-styrene oxide primarily to thesame enantiomer, (R)-1- phenyl-1,2-Ethanediol (22 � 1 mmol/min/mg), with an enantiomeric ratio of 40 � 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)-1-phenyl-1,2-Ethanediol at 4.7 � 0.7 mmol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid
Zhen Yang - One of the best experts on this subject based on the ideXlab platform.
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isobaric vapor liquid equilibrium of ethanenitrile water 1 2 Ethanediol 1 ethyl 3 methylimidazolium chloride
Fluid Phase Equilibria, 2014Co-Authors: Huan Liu, Xianbao Cui, Ying Zhang, Tianyang Feng, Zhen YangAbstract:Abstract The vapor–liquid equilibrium (VLE) data for the quaternary system ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) were measured at 102.5 kPa. The experimental VLE data were correlated with the nonrandom two liquid (NRTL) activity coefficient model, and the binary interaction parameters were obtained. The results show that the mixed entrainer of [EMIM]Cl and 1,2-Ethanediol can eliminate the azeotropic point of ethanenitrile and water; the selectivity of [EMIM]Cl is higher than that of 1,2-Ethanediol; the relative volatility of ethanenitrile to water increases with the increase of the mole fraction of mixed solvent (1,2-Ethanediol + [EMIM]Cl) and the amount of [EMIM]Cl in mixed solvent, but there is no synergetic effect between 1,2-Ethanediol and [EMIM]Cl. The main functions of 1,2-Ethanediol are to dissolve ionic liquid and to reduce the viscosity of the entrainer.
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Isobaric vapor–liquid equilibrium of ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride
Fluid Phase Equilibria, 2014Co-Authors: Liu Huan, Xianbao Cui, Ying Zhang, Tianyang Feng, Zhen YangAbstract:Abstract The vapor–liquid equilibrium (VLE) data for the quaternary system ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) were measured at 102.5 kPa. The experimental VLE data were correlated with the nonrandom two liquid (NRTL) activity coefficient model, and the binary interaction parameters were obtained. The results show that the mixed entrainer of [EMIM]Cl and 1,2-Ethanediol can eliminate the azeotropic point of ethanenitrile and water; the selectivity of [EMIM]Cl is higher than that of 1,2-Ethanediol; the relative volatility of ethanenitrile to water increases with the increase of the mole fraction of mixed solvent (1,2-Ethanediol + [EMIM]Cl) and the amount of [EMIM]Cl in mixed solvent, but there is no synergetic effect between 1,2-Ethanediol and [EMIM]Cl. The main functions of 1,2-Ethanediol are to dissolve ionic liquid and to reduce the viscosity of the entrainer.
Wilfred Chen - One of the best experts on this subject based on the ideXlab platform.
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enantioconvergent production of r 1 phenyl 1 2 Ethanediol from styrene oxide by combining the solanum tuberosum and an evolved agrobacterium radiobacter ad1 epoxide hydrolases
Biotechnology and Bioengineering, 2006Co-Authors: Wilfred Chen, Thomas K WoodAbstract:Solubleepoxidehydrolase(EH)fromthepotato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA-I219F, were pur- ified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)-1-phenyl-1,2- Ethanediol, which is an important intermediate for pharmaceuticals. EchA-I219F has enhanced enantioselec- tivity (enantiomeric ratio of 91 based on products) for converting (R)-styrene oxide to (R)-1-phenyl-1,2-ethane- diol (2.0 � 0.2 mmol/min/mg), and the potato EH converts (S)-styrene oxide primarily to thesame enantiomer, (R)-1- phenyl-1,2-Ethanediol (22 � 1 mmol/min/mg), with an enantiomeric ratio of 40 � 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)-1-phenyl-1,2-Ethanediol at 4.7 � 0.7 mmol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid
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Enantioconvergent production of (R)‐1‐phenyl‐1,2‐Ethanediol from styrene oxide by combining the Solanum tuberosum and an evolved Agrobacterium radiobacter AD1 epoxide hydrolases
Biotechnology and bioengineering, 2006Co-Authors: Li Cao, Wilfred Chen, Jintae Lee, Thomas K WoodAbstract:Solubleepoxidehydrolase(EH)fromthepotato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA-I219F, were pur- ified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)-1-phenyl-1,2- Ethanediol, which is an important intermediate for pharmaceuticals. EchA-I219F has enhanced enantioselec- tivity (enantiomeric ratio of 91 based on products) for converting (R)-styrene oxide to (R)-1-phenyl-1,2-ethane- diol (2.0 � 0.2 mmol/min/mg), and the potato EH converts (S)-styrene oxide primarily to thesame enantiomer, (R)-1- phenyl-1,2-Ethanediol (22 � 1 mmol/min/mg), with an enantiomeric ratio of 40 � 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)-1-phenyl-1,2-Ethanediol at 4.7 � 0.7 mmol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid
Rinaldo Marini Bettolo - One of the best experts on this subject based on the ideXlab platform.
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Unexpected Racemization in the Course of the Acetalization of (+)-(S)-5-Methyl-Wieland–Miescher Ketone with 1,2-Ethanediol and TsOH under Classical Experimental Conditions
International journal of molecular sciences, 2019Co-Authors: Francesca Leonelli, Irene Piergentili, Giulio Lucarelli, Luisa Maria Migneco, Rinaldo Marini BettoloAbstract:(+)-(S) and (-)-(R)-5-methyl-Wieland-Miescher ketone (+)-1 and (-)-1, are important synthons in the diastereo and enantioselective syntheses of biological and/or pharmacological interesting compounds. A key step in these syntheses is the chemoselective C(1)O acetalization to (+)-5 and (-)-5, respectively. Various procedures for this transformation have been described in the literature. Among them, the classical procedure based on the use of 1,2-Ethanediol and TsOH in refluxing benzene in the presence of a Dean-Stark apparatus. Within our work on bioactive natural products, it occurred to us to observe the partial racemization of (+)-5 in the course of the acetalization of (+)-1 by means of the latter methodology. Aiming to investigate this drawback, which, to our best knowledge, has no precedents in the literature, we acetalized with 1,2-Ethanediol and TsOH in refluxing benzene and in the presence of a Dean-Stark apparatus under various experimental conditions, enantiomerically pure (+)-1. It was found that the extent of racemization depends on the TsOH/(+)-1 and 1,2-Ethanediol/(+)-1 ratios. Mechanism hypotheses for this partial and unexpected racemization are provided.
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unexpected racemization in the course of the acetalization of s 5 methyl wieland miescher ketone with 1 2 Ethanediol and tsoh under classical experimental conditions
International Journal of Molecular Sciences, 2019Co-Authors: Francesca Leonelli, Irene Piergentili, Giulio Lucarelli, Luisa Maria Migneco, Rinaldo Marini BettoloAbstract:(+)-(S) and (-)-(R)-5-methyl-Wieland-Miescher ketone (+)-1 and (-)-1, are important synthons in the diastereo and enantioselective syntheses of biological and/or pharmacological interesting compounds. A key step in these syntheses is the chemoselective C(1)O acetalization to (+)-5 and (-)-5, respectively. Various procedures for this transformation have been described in the literature. Among them, the classical procedure based on the use of 1,2-Ethanediol and TsOH in refluxing benzene in the presence of a Dean-Stark apparatus. Within our work on bioactive natural products, it occurred to us to observe the partial racemization of (+)-5 in the course of the acetalization of (+)-1 by means of the latter methodology. Aiming to investigate this drawback, which, to our best knowledge, has no precedents in the literature, we acetalized with 1,2-Ethanediol and TsOH in refluxing benzene and in the presence of a Dean-Stark apparatus under various experimental conditions, enantiomerically pure (+)-1. It was found that the extent of racemization depends on the TsOH/(+)-1 and 1,2-Ethanediol/(+)-1 ratios. Mechanism hypotheses for this partial and unexpected racemization are provided.
Xianbao Cui - One of the best experts on this subject based on the ideXlab platform.
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isobaric vapor liquid equilibrium of ethanenitrile water 1 2 Ethanediol 1 ethyl 3 methylimidazolium chloride
Fluid Phase Equilibria, 2014Co-Authors: Huan Liu, Xianbao Cui, Ying Zhang, Tianyang Feng, Zhen YangAbstract:Abstract The vapor–liquid equilibrium (VLE) data for the quaternary system ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) were measured at 102.5 kPa. The experimental VLE data were correlated with the nonrandom two liquid (NRTL) activity coefficient model, and the binary interaction parameters were obtained. The results show that the mixed entrainer of [EMIM]Cl and 1,2-Ethanediol can eliminate the azeotropic point of ethanenitrile and water; the selectivity of [EMIM]Cl is higher than that of 1,2-Ethanediol; the relative volatility of ethanenitrile to water increases with the increase of the mole fraction of mixed solvent (1,2-Ethanediol + [EMIM]Cl) and the amount of [EMIM]Cl in mixed solvent, but there is no synergetic effect between 1,2-Ethanediol and [EMIM]Cl. The main functions of 1,2-Ethanediol are to dissolve ionic liquid and to reduce the viscosity of the entrainer.
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Isobaric vapor–liquid equilibrium of ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride
Fluid Phase Equilibria, 2014Co-Authors: Liu Huan, Xianbao Cui, Ying Zhang, Tianyang Feng, Zhen YangAbstract:Abstract The vapor–liquid equilibrium (VLE) data for the quaternary system ethanenitrile + water + 1,2-Ethanediol + 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) were measured at 102.5 kPa. The experimental VLE data were correlated with the nonrandom two liquid (NRTL) activity coefficient model, and the binary interaction parameters were obtained. The results show that the mixed entrainer of [EMIM]Cl and 1,2-Ethanediol can eliminate the azeotropic point of ethanenitrile and water; the selectivity of [EMIM]Cl is higher than that of 1,2-Ethanediol; the relative volatility of ethanenitrile to water increases with the increase of the mole fraction of mixed solvent (1,2-Ethanediol + [EMIM]Cl) and the amount of [EMIM]Cl in mixed solvent, but there is no synergetic effect between 1,2-Ethanediol and [EMIM]Cl. The main functions of 1,2-Ethanediol are to dissolve ionic liquid and to reduce the viscosity of the entrainer.
