Enzyme-catalyzed asymmetric synthesis of optically active (R)- and (S)-ethyl -4-phenyl-4-hydroxybutyrate with microbial cells

Abstract

In efforts to obtain carbonyl reductases with high activity and enantioselectivity, forty microorganisms belonging to different taxonomical groups were investigated for the ability to catalyze the enantioselective reduction of ethyl 4-phenyl- 4-oxobutyrate (EPOB) to the corresponding optically active ethyl 4-phenyl-4-hydroxybutyrate (EPHB). Highly enantioselective reduction of EPOB was achieved with Candida magnoliae CGMCC 2.1919 and Saccharomyces cerevisiae CGMCC 2.399 giving the corresponding (R)-EPHB and (S)-EPHB in 99% ee, respectively. The highly enantioselective bioreductions provide simple routes to optically active γ-hydroxyl acid esters that are useful pharmaceutical intermediates and versatile chiral building blocks.

Keywords::

• Bioreduction
• Candida magnoliae
• Saccharomyces cerevisiae
• Enantioselectivity

Acknowledgments

We are grateful for the financial support obtained from The Education Department of Guizhou Province, China (Project No. Qian Jiao Ke 2010046); the Organization Department of the Provincial Committee of Guizhou Province (Project No. TZJF-2010-063); and the Technological Activities of Certification for the Returned Oversea Students from the Department of Human Resources and the Social Security (No. 2011-1) and Natural Science Foundation Project of CQ CSTC, Project No. 2009BB5286.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.