scholarly journals Enantioselective Hydrolysis of Styrene Oxide and Benzyl Glycidyl Ether by a Variant of Epoxide Hydrolase from Agromyces mediolanus

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 367
Author(s):  
Jin ◽  
Li ◽  
Zhang ◽  
Lin ◽  
Yang ◽  
...  
Keyword(s):  
Epoxide Hydrolase ◽  
Kinetic Resolution ◽  
Styrene Oxide ◽  
Glycidyl Ether ◽  
Enantiomeric Excess ◽  
Docking Simulation ◽  
Optically Active ◽  
Tween 20 ◽  
Enantioselective Hydrolysis ◽  
Enantiopure Epoxides

Enantiopure epoxides are versatile synthetic intermediates for producing optically active pharmaceuticals. In an effort to provide more options for the preparation of enantiopure epoxides, a variant of the epoxide hydrolase (vEH-Am) gene from a marine microorganism Agromyces mediolanus was synthesized and expressed in Escherichia coli. Recombiant vEH-Am displayed a molecular weight of 43 kDa and showed high stability with a half-life of 51.1 h at 30 °C. The purified vEH-Am exhibited high enantioselectivity towards styrene oxide (SO) and benzyl glycidyl ether (BGE). The vEH-Am preferentially converted (S)-SO, leaving (R)-SO with the enantiomeric excess (ee) >99%. However, (R)-BGE was preferentially hydrolyzed by vEH-Am, resulting in (S)-BGE with >99% ee. To investigate the origin of regioselectivity, the interactions between vEH-Am and enantiomers of SO and BGE were analyzed by molecular docking simulation. In addition, it was observed that the yields of (R)-SO and (S)-BGE decreased with the increase of substrate concentrations. The yield of (R)-SO was significantly increased by adding 2% (v/v) Tween-20 or intermittent supplementation of the substrate. To our knowledge, vEH-Am displayed the highest enantioselectivity for the kinetic resolution of racemic BGE among the known EHs, suggesting promising applications of vEH-Am in the preparation of optically active BGE.

Preparative-scale kinetic resolution of racemic styrene oxide by immobilized epoxide hydrolase

2011 ◽  
Vol 49 (6-7) ◽  
pp. 555-559 ◽  
Author(s):  
Deniz Yildirim ◽  
S. Seyhan Tükel ◽  
Dilek Alagöz ◽  
Özlem Alptekin
Keyword(s):  
Epoxide Hydrolase ◽  
Kinetic Resolution ◽  
Styrene Oxide ◽  
Preparative Scale

Enantioselective hydrolysis of racemic styrene oxide by epoxide hydrolase ofRhodosporidium kratochvilovae SYU-08

2003 ◽  
Vol 8 (5) ◽  
pp. 306-308 ◽  
Author(s):  
Ji Won Lee ◽  
Eun Jung Lee ◽  
Seung Sik Yoo ◽  
Sung Hoon Park ◽  
Hee Sook Kim ◽  
...  
Keyword(s):  
Epoxide Hydrolase ◽  
Styrene Oxide ◽  
Enantioselective Hydrolysis ◽  
Hydrolysis Of

Isolation of an esterase-producing Trichosporon brassicae and its catalytic performance in kinetic resolution of ketoprofen

2001 ◽  
Vol 47 (12) ◽  
pp. 1101-1106 ◽  
Author(s):  
Duan Shen ◽  
Jian-He Xu ◽  
Peng-Fei Gong ◽  
Hui-Yuan Wu ◽  
You-Yan Liu
Keyword(s):  
Ethyl Ester ◽  
Sole Carbon Source ◽  
Kinetic Resolution ◽  
Enantiomeric Excess ◽  
Catalytic Performance ◽  
Soil Samples ◽  
Enantioselective Hydrolysis ◽  
Resting Cells ◽  
Enantiomeric Ratio ◽  
Hydrolysis Of

A yeast strain CGMCC 0574, identified as Trichosporon brassicae, was selected from 92 strains for its high (S) selectivity in the hydrolysis of ketoprofen ethyl ester. The effective strains of the microorganisms were isolated from soil samples with the ester as the sole carbon source. The ethyl ester proved to be the best substrate for resolution of ketoprofen among several ketoprofen esters examined. The resting cells of CGMCC 0574 could catalyze the hydrolysis of ketoprofen ethyl ester with an enantiomeric ratio of 44.9, giving (S)-ketoprofen an enantiomeric excess of 91.5% at 42% conversion.Key words: ketoprofen, biocatalytic resolution, enantioselective hydrolysis, microbial esterase, Trichosporon brassicae.

Total asymmetric syntheses of (1S,2S)-norcoronamic acid, and of (1R,2R)- and (1S,2S)-coronamic acids from the diastereoselective cyclization of 2-(N-benzylideneamino)-4-chlorobutyronitriles

1994 ◽  
Vol 72 (5) ◽  
pp. 1312-1327 ◽  
Author(s):  
Anne Gaucher ◽  
Jean Ollivier ◽  
Jacqueline Marguerite ◽  
Renée Paugam ◽  
Jacques Salaün
Keyword(s):  
Acid Hydrolysis ◽  
Butyl Acetate ◽  
Molecular Mechanic ◽  
Enantiomeric Excess ◽  
Optically Active ◽  
Chiral Auxiliary ◽  
Enantioselective Hydrolysis ◽  
Asymmetric Syntheses ◽  
Methyl Propionate ◽  
Stereogenic Centers

(3R)-2-(N-Benzylideneamino)-4-chloro-3-methylbutyronitrile 3, prepared from the commercially available methyl (2S)-3-hydroxy-2-methyl propionate 5 (96% ee), readily underwent potassium carbonate induced cyclization to provide, after acid hydrolysis (6 N HCl) and chromatography, the (1S,2S)-norcoronamic acid 1a with 88% diastereoselectivity and > 95% enantiomeric excess. From (2R)-2-(hydroxymethyl)butyl acetate 23 (> 88% ee) obtained by enzymatic enantioselective hydrolysis with lipase PS, was prepared the (3S)-2-(N-benzylideneamino)-3-(chloromethyl)valeronitrile 29, which after base-induced cyclization (K2CO3) and acid (6 N HCl) or basic (0.8 N NaOH) hydrolysis led to the non-natural (1R,2R)-coronamic acid 18 (> 88% ee). Also from this same acetate (2R)-23 was prepared the (3R)-3-(chloromethyl)-2-[(diphenylmethylene)amino]pentanenitrile 37, which provided the (1S,2S)-coronamic acid 17 (> 88% ee) after base-induced cyclization (K2CO3 or LDA) and acid hydrolysis (6 N HCl). It is noteworthy that these short synthetic sequences, which do not require any expensive chiral auxiliary or optically active precursors, do not alter the enantiomeric purity of the stereogenic centers of these 2,3-methanoamino acids. However, the E diastereoselectivity of these cyclizations was not improved by using bulky N-(diphenylmethylene)amino substituent, contrary to results of some molecular mechanic calculations (MAD).

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