Gram-Scale Synthesis of (R) -P- Chlorophenyl-1,2-Ethanediol at High Concentration by a Pair of Epoxide Hydrolases

Dong Zhang; Yuqing Lei; Tingting Wang; Wenqian Lin; Xingyi Chen; Minchen Wu

doi:10.3389/fbioe.2022.824300

Gram-Scale Synthesis of (R) -P- Chlorophenyl-1,2-Ethanediol at High Concentration by a Pair of Epoxide Hydrolases

Front Bioeng Biotechnol. 2022 Feb 28:10:824300. doi: 10.3389/fbioe.2022.824300. eCollection 2022.

Authors

Dong Zhang¹, Yuqing Lei¹, Tingting Wang², Wenqian Lin¹, Xingyi Chen³, Minchen Wu³

Affiliations

¹ Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
² Yancheng Juheng Road Primary School, Yancheng, China.
³ Wuxi School of Medicine, Jiangnan University, Wuxi, China.

Abstract

(R)-p-chlorophenyl-1,2-ethanediol (pCPED) is an important intermediate for the synthesis of (R)-eliprodil that is widely applied in the treatment of ischemic stroke. To prepare (R)-pCPED with high enantiomeric excess (ee _p) and yield via the enantioconvergent hydrolysis of racemic styrene oxide (rac-pCSO) at high concentration, the bi-enzymatic catalysis was designed and investigated by a pair of epoxide hydrolases, a mutant (PvEH1^Z4X4-59) of Phaseolus vulgaris EH1 and a mutant (RpEH^F361V) of Rhodotorula paludigena RpEH. Firstly, the maximum allowable concentration of rac-pCSO was confirmed. Subsequently, the addition mode and the weight ratio of two Escherichia coli cells were optimized. Finally, under the optimized reaction conditions-the cell weight ratio 20:1 of E. coli/pveh1^z4x4-59 to E. coli/rpeh ^F361V, a simultaneous addition mode, and reaction temperature at 25°C-300 mM rac-pCSO in the 100 ml 4% (v/v) Tween-20/phosphate buffer system (100 mM, pH 7.0) was completely hydrolyzed within 5 h, affording (R)-pCPED with 87.8% ee _p, 93.4% yield, and 8.63 g/L/h space-time yield (STY). This work would be an efficient technical strategy for the preparation of chiral vicinal diols at industrial scale.

Keywords: bi-enzymatic catalysis; enantioconvergent hydrolysis; epoxide hydrolase; high substrate concentration; kinetic resolution.