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Yankui Yu - One of the best experts on this subject based on the ideXlab platform.
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asymmetric reduction of acetophenone into r 1 Phenylethanol by endophytic fungus neofusicoccum parvum byef07 isolated from illicium verum
Biochemical and Biophysical Research Communications, 2016Co-Authors: Haiyun Li, Ziyuan Li, Guihua Ruan, Yankui YuAbstract:Seventy-nine strains of endophytic fungi isolated from the healthy leaves, twigs and fruits of Illicium verum were screened for the asymmetric reduction activities to acetophenone. Strain BYEF07, which showed relatively high reduction activities, has been classified as Neofusicoccum parvum, and the main product was confirmed to be (R)-(+)-1-Phenylethanol by GC–MS and chiral HPLC methods. The bio-reduction conditions of acetophenone by cells of N. parvum BYEF07 were investigated in detail. Under the conditions of 1.8 g/L of acetophenone, 100 g/L of microorganism cells and 10 g/L of glucose in 40 mL Na2HPO4 KH2PO4 buffer solution at pH7.5, 30 °C and 150 rpm, after 48 h reaction, the production yield of 1-Phenylethanol and enantiomeric excess value of (R)-(+)-1-Phenylethanol were 78% and 96%, respectively.
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Asymmetric reduction of acetophenone into R-(+)-1-Phenylethanol by endophytic fungus Neofusicoccum parvum BYEF07 isolated from Illicium verum.
Biochemical and Biophysical Research Communications, 2016Co-Authors: Haiyun Li, Ziyuan Li, Guihua Ruan, Yankui YuAbstract:Seventy-nine strains of endophytic fungi isolated from the healthy leaves, twigs and fruits of Illicium verum were screened for the asymmetric reduction activities to acetophenone. Strain BYEF07, which showed relatively high reduction activities, has been classified as Neofusicoccum parvum, and the main product was confirmed to be (R)-(+)-1-Phenylethanol by GC–MS and chiral HPLC methods. The bio-reduction conditions of acetophenone by cells of N. parvum BYEF07 were investigated in detail. Under the conditions of 1.8 g/L of acetophenone, 100 g/L of microorganism cells and 10 g/L of glucose in 40 mL Na2HPO4 KH2PO4 buffer solution at pH7.5, 30 °C and 150 rpm, after 48 h reaction, the production yield of 1-Phenylethanol and enantiomeric excess value of (R)-(+)-1-Phenylethanol were 78% and 96%, respectively.
Junwei An - One of the best experts on this subject based on the ideXlab platform.
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oxidative kinetic resolution of 1 Phenylethanol catalyzed by sugar based salen mn iii complexes
Carbohydrate Research, 2008Co-Authors: Jiquan Zhao, Yuecheng Zhang, Weiyu Wang, Junwei AnAbstract:Abstract Three new chiral salen–Mn(III) complexes with sugars at the C-5(5′) positions of the salicylaldehyde moieties of the salen ligand were synthesized. Their structures were characterized by FTIR, MS, and elemental analysis. The complexes together with two previously reported ones were successfully used as chiral catalysts for the oxidative kinetic resolution (OKR) of 1-Phenylethanol using PhI(OAc) 2 as an oxidant and KBr as an additive. Excellent enantiomeric excess (up to 89%) of the product was achieved in 0.5 h at 20 °C. The results showed that the sugars at C-5(5′) of salicylaldehyde moieties in the ligand had influences on the catalytic performances of the complexes. It was concluded that the sugars with the same rotation direction of polarized light as the diimine bridge within the complex could enhance the chiral induction of the complex in the OKR of 1-Phenylethanol, but the sugars with the opposite one would reduce that of the corresponding complex.
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Oxidative kinetic resolution of 1-Phenylethanol catalyzed by sugar-based salen–Mn(III) complexes
Carbohydrate Research, 2008Co-Authors: Jiquan Zhao, Yuecheng Zhang, Weiyu Wang, Junwei AnAbstract:Abstract Three new chiral salen–Mn(III) complexes with sugars at the C-5(5′) positions of the salicylaldehyde moieties of the salen ligand were synthesized. Their structures were characterized by FTIR, MS, and elemental analysis. The complexes together with two previously reported ones were successfully used as chiral catalysts for the oxidative kinetic resolution (OKR) of 1-Phenylethanol using PhI(OAc) 2 as an oxidant and KBr as an additive. Excellent enantiomeric excess (up to 89%) of the product was achieved in 0.5 h at 20 °C. The results showed that the sugars at C-5(5′) of salicylaldehyde moieties in the ligand had influences on the catalytic performances of the complexes. It was concluded that the sugars with the same rotation direction of polarized light as the diimine bridge within the complex could enhance the chiral induction of the complex in the OKR of 1-Phenylethanol, but the sugars with the opposite one would reduce that of the corresponding complex.
Haiyun Li - One of the best experts on this subject based on the ideXlab platform.
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asymmetric reduction of acetophenone into r 1 Phenylethanol by endophytic fungus neofusicoccum parvum byef07 isolated from illicium verum
Biochemical and Biophysical Research Communications, 2016Co-Authors: Haiyun Li, Ziyuan Li, Guihua Ruan, Yankui YuAbstract:Seventy-nine strains of endophytic fungi isolated from the healthy leaves, twigs and fruits of Illicium verum were screened for the asymmetric reduction activities to acetophenone. Strain BYEF07, which showed relatively high reduction activities, has been classified as Neofusicoccum parvum, and the main product was confirmed to be (R)-(+)-1-Phenylethanol by GC–MS and chiral HPLC methods. The bio-reduction conditions of acetophenone by cells of N. parvum BYEF07 were investigated in detail. Under the conditions of 1.8 g/L of acetophenone, 100 g/L of microorganism cells and 10 g/L of glucose in 40 mL Na2HPO4 KH2PO4 buffer solution at pH7.5, 30 °C and 150 rpm, after 48 h reaction, the production yield of 1-Phenylethanol and enantiomeric excess value of (R)-(+)-1-Phenylethanol were 78% and 96%, respectively.
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Asymmetric reduction of acetophenone into R-(+)-1-Phenylethanol by endophytic fungus Neofusicoccum parvum BYEF07 isolated from Illicium verum.
Biochemical and Biophysical Research Communications, 2016Co-Authors: Haiyun Li, Ziyuan Li, Guihua Ruan, Yankui YuAbstract:Seventy-nine strains of endophytic fungi isolated from the healthy leaves, twigs and fruits of Illicium verum were screened for the asymmetric reduction activities to acetophenone. Strain BYEF07, which showed relatively high reduction activities, has been classified as Neofusicoccum parvum, and the main product was confirmed to be (R)-(+)-1-Phenylethanol by GC–MS and chiral HPLC methods. The bio-reduction conditions of acetophenone by cells of N. parvum BYEF07 were investigated in detail. Under the conditions of 1.8 g/L of acetophenone, 100 g/L of microorganism cells and 10 g/L of glucose in 40 mL Na2HPO4 KH2PO4 buffer solution at pH7.5, 30 °C and 150 rpm, after 48 h reaction, the production yield of 1-Phenylethanol and enantiomeric excess value of (R)-(+)-1-Phenylethanol were 78% and 96%, respectively.
Johann Heider - One of the best experts on this subject based on the ideXlab platform.
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asymmetric reduction of ketones and β keto esters by s 1 Phenylethanol dehydrogenase from denitrifying bacterium aromatoleum aromaticum
Applied Microbiology and Biotechnology, 2015Co-Authors: Agnieszka Dudzik, Johann Heider, Wojciech Snoch, Pawel Borowiecki, J Opalinskapiskorz, Malgorzata Witko, Maciej SzaleniecAbstract:Enzyme-catalyzed enantioselective reductions of ketones and keto esters have become popular for the production of homochiral building blocks which are valuable synthons for the preparation of biologically active compounds at industrial scale. Among many kinds of biocatalysts, dehydrogenases/reductases from various microorganisms have been used to prepare optically pure enantiomers from carbonyl compounds. (S)-1-Phenylethanol dehydrogenase (PEDH) was found in the denitrifying bacterium Aromatoleum aromaticum (strain EbN1) and belongs to the short-chain dehydrogenase/reductase family. It catalyzes the stereospecific oxidation of (S)-1-Phenylethanol to acetophenone during anaerobic ethylbenzene mineralization, but also the reverse reaction, i.e., NADH-dependent enantioselective reduction of acetophenone to (S)-1-Phenylethanol. In this work, we present the application of PEDH for asymmetric reduction of 42 prochiral ketones and 11 β-keto esters to enantiopure secondary alcohols. The high enantioselectivity of the reaction is explained by docking experiments and analysis of the interaction and binding energies of the theoretical enzyme-substrate complexes leading to the respective (S)- or (R)-alcohols. The conversions were carried out in a batch reactor using Escherichia coli cells with heterologously produced PEDH as whole-cell catalysts and isopropanol as reaction solvent and cosubstrate for NADH recovery. Ketones were converted to the respective secondary alcohols with excellent enantiomeric excesses and high productivities. Moreover, the progress of product formation was studied for nine para-substituted acetophenone derivatives and described by neural network models, which allow to predict reactor behavior and provides insight on enzyme reactivity. Finally, equilibrium constants for conversion of these substrates were derived from the progress curves of the reactions. The obtained values matched very well with theoretical predictions.
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Crystal Structure and Enzyme Kinetics of the (S)-Specific 1-Phenylethanol Dehydrogenase of the Denitrifying Bacterium Strain EbN1†,‡
Biochemistry, 2006Co-Authors: H. Wolfgang Höffken, Minh Duong, Thomas Friedrich, Michael Breuer, Bernhard Hauer, Richard Reinhardt, Ralf Rabus, Johann HeiderAbstract:(S)-1-Phenylethanol dehydrogenase (PED) from the denitrifying bacterium strain EbN1 catalyzes the NAD+-dependent, stereospecific oxidation of (S)-1-Phenylethanol to acetophenone and the biotechnologically interesting reverse reaction. This novel enzyme belongs to the short-chain alcohol dehydrogenase/aldehyde reductase family. The coding gene (ped) was heterologously expressed in Escherichia coli and the purified protein was crystallized. The X-ray structures of the apo-form and the NAD+-bound form were solved at a resolution of 2.1 and 2.4 A, respectively, revealing that the enzyme is a tetramer with two types of hydrophobic dimerization interfaces, similar to β-oxoacyl-[acyl carrier protein] reductase (FabG) from E. coli. NAD+-binding is associated with a conformational shift of the substrate binding loop of PED from a crystallographically unordered “open” to a more ordered “closed” form. Modeling the substrate acetophenone into the active site revealed the structural prerequisites for the strong enanti...
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crystal structure and enzyme kinetics of the s specific 1 Phenylethanol dehydrogenase of the denitrifying bacterium strain ebn1
Biochemistry, 2006Co-Authors: Wolfgang H Hoffken, Minh Duong, Thomas Friedrich, Michael Breuer, Bernhard Hauer, Richard Reinhardt, Ralf Rabus, Johann HeiderAbstract:(S)-1-Phenylethanol dehydrogenase (PED) from the denitrifying bacterium strain EbN1 catalyzes the NAD+-dependent, stereospecific oxidation of (S)-1-Phenylethanol to acetophenone and the biotechnologically interesting reverse reaction. This novel enzyme belongs to the short-chain alcohol dehydrogenase/aldehyde reductase family. The coding gene (ped) was heterologously expressed in Escherichia coli and the purified protein was crystallized. The X-ray structures of the apo-form and the NAD+-bound form were solved at a resolution of 2.1 and 2.4 A, respectively, revealing that the enzyme is a tetramer with two types of hydrophobic dimerization interfaces, similar to β-oxoacyl-[acyl carrier protein] reductase (FabG) from E. coli. NAD+-binding is associated with a conformational shift of the substrate binding loop of PED from a crystallographically unordered “open” to a more ordered “closed” form. Modeling the substrate acetophenone into the active site revealed the structural prerequisites for the strong enanti...
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s 1 Phenylethanol dehydrogenase of azoarcus sp strain ebn1 an enzyme of anaerobic ethylbenzene catabolism
Archives of Microbiology, 2001Co-Authors: Olaf Kniemeyer, Johann HeiderAbstract:The initial steps in the anaerobic oxidation of the aromatic hydrocarbon ethylbenzene by denitrifying bacteria are two sequential dehydrogenation reactions of ethylbenzene to (S)-1-Phenylethanol and further to acetophenone. The enzyme catalysing the second oxidation step, (S)-1-Phenylethanol dehydrogenase, was analysed in the denitrifying bacterium Azoarcus sp. strain EbN1. An NAD+-dependent 1-Phenylethanol dehydrogenase for each of the enantiomers of 1-Phenylethanol was identified in this bacterium; the two enzymes were induced under different growth conditions. (S)-1-Phenylethanol dehydrogenase from ethylbenzene-grown cells was purified and biochemically characterised. The enzyme is a typical secondary alcohol dehydrogenase and consists of two subunits of 25.5 kDa. The enantioselective enzyme catalyses the oxidation of (S)-1-Phenylethanol or the reduction of acetophenone and is inhibited by high concentrations of (R)-1-Phenylethanol. The enzyme exhibits low apparent Km values for (S)-1-Phenylethanol and acetophenone and is rather substrate-specific, using only a few chemically similar secondary alcohols, such as 1-phenylpropanol and isopropanol.
Vicente Gotor - One of the best experts on this subject based on the ideXlab platform.
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Laccase/TEMPO-mediated system for the thermodynamically disfavored oxidation of 2,2-dihalo-1-Phenylethanol derivatives
Green Chemistry, 2014Co-Authors: Kinga Kędziora, Alba Díaz-rodríguez, Iván Lavandera, Vicente Gotor-fernández, Vicente GotorAbstract:An efficient methodology to oxidize β,β-dihalogenated secondary alcohols employing oxygen was achieved in a biphasic medium using the laccase from Trametes versicolor/TEMPO pair, providing the corresponding ketones in a clean fashion under very mild conditions. Moreover, a chemoenzymatic protocol has been applied successfully to deracemize 2,2-dichloro-1-Phenylethanol combining this oxidation with an alcohol dehydrogenase-catalyzed bioreduction.
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laccase tempo mediated system for the thermodynamically disfavored oxidation of 2 2 dihalo 1 Phenylethanol derivatives
Green Chemistry, 2014Co-Authors: Kinga Kedziora, Iván Lavandera, Alba Diazrodriguez, Vicente Gotorfernandez, Vicente GotorAbstract:An efficient methodology to oxidize β,β-dihalogenated secondary alcohols employing oxygen was achieved in a biphasic medium using the laccase from Trametes versicolor/TEMPO pair, providing the corresponding ketones in a clean fashion under very mild conditions. Moreover, a chemoenzymatic protocol has been applied successfully to deracemize 2,2-dichloro-1-Phenylethanol combining this oxidation with an alcohol dehydrogenase-catalyzed bioreduction.
