Efficient synthesis of (S)-epichlorohydrin in high yield by cascade biocatalysis with halohydrin dehalogenase and epoxide hydrolase mutants

Enantioselective biotransformation of prochiral 1,3-DCP by halohydrin dehalogenases (HHDHs) is particularly attractive since 100% yield of chiral epichlorohydrin (ECH) may be obtained. HheC mutant (P175S/W249P) displayed greatly improved enantiomeric excess (ee) of (S)-ECH from 5% to 95.3% in the catalyzed dehalogenation of 1,3-DCP at pH 8.0. (S)-ECH was enantioselectively biotransformed from 40 mM 1,3-DCP with 92.3% ee and 93.2% yield at pH 10.0. To increase the ee of (S)-ECH, the catalysis was carried out using HheC mutant coupled with epoxide hydrolase mutant and the maximum yield and ee of (S)-ECH reached 91.2% and >99%. (C) 2015 Elsevier B.V. All rights reserved.