生物催化不对称还原法制备(R)-和(S)-2-羟基-4-苯基丁酸乙酯

用全细胞催化法合成2-羟基-4-苯基丁酸乙酯(EHPB)的两种对映异构体。筛选得到两株高立体选择性菌株,能催化前手性酮还原分别生产相应的手性醇。考察了这两株菌株的反应特性,得到了合适的反应条件:菌株短小芽孢杆菌(Bacillus pumilusPhe-C3),反应24 h,底物浓度25 mmol/L,体系pH7.0,温度30℃,R-EHPB的产率达74.5%,对映体过量值(e.e.)达97%;菌株肺炎克雷伯菌(Klebsiella pneumomiaePhe-E4),反应20 h,底物浓度15 mmol/L,体系pH7.0,温度30℃,S-EHPB的产率达71.7%,e.e.达95%。

Enzymatic Synthesis of Both Enantiomers of Ethyl 2-Hydroxy-4-phenylbutanoate

Both enantiomers of ethyl 2-hydroxy-4-phenylbutanoate(EHPB) were prepared by enzymatic reduction of ethyl 2-oxo-4-phenylbutanoate(EOPB) with two whole cells in present work.Two strains capable to reduce the ketone to the corresponding chiral alcohols were screened.The reaction conditions were optimized.The R-enantiomer was obtained in 74.5% yield with 97% e.e.under the catalysis of 25 mmol/L substrate by strain Bacillus pumilus Phe-C3;the S-enantiomer was achieved in 71.7% yield with 95% e.e.under the catalysis of 15 mmol/L substrate by strain Klebsiella pneumomiae Phe-E4.