南海深海微生物酯酶EST12-7在制备(R)-2-氯丙酸乙酯中的应用研究

利用来源南海深海的微生物酯酶EST12-7不对称水解反应拆分制备（R）-2-氯丙酸乙酯。并探寻了温度、pH、底物浓度、有机溶剂和反应时间等因素对酯酶EST12-7催化制备（R）-2-氯丙酸乙酯的影响。结果表明，深海微生物酯酶EST12-7催化制备（R）-2-氯丙酸乙酯的最佳反应条件为：13.8 μg/ml酯酶EST12-7，50 mmol/L（±）-2-氯丙酸乙酯，2%正癸醇，pH8.5，30℃，0.05mol/L Tris-HCl，反应60 min。在最佳反应条件下，（±）-2-氯丙酸乙酯的转化率可达49%，所制备的（R）-2-氯丙酸乙酯的光学纯度为98%。通过对酯酶EST12-7拆分制备（R）-2-氯丙酸甲酯和（R）-2-氯丙酸乙酯进行比较，2-氯丙酸酯中的链长对酯酶EST12-7拆分反应有极大的影响。

Utilization of a Marine Microbial Esterase in the Enantio-selective Preparation of (R)-Ethyl 2-chloropropionate

The esterase EST12-7 was identified from the deep sea of the South China Sea and was used to prepared (R)-ethyl 2-chloropropionate efficiently through asymmetric hydrolysis reactions. The effects of temperature, pH, substrate concentration, organic solvents and reaction time on the preparation of (R)-ethyl 2-chloropropinate catalyzed by EST12-7 were investigated. The results identified that the optimal working conditions for the preparation of (R)-ethyl 2-chloropropinate using deep-sea microbial esterase EST12-7 were that: 13.8 μg/ml esterase EST12-7, 50 mmol/L (±)-ethyl 2-chloropropinate, 2% n-decyl alcohol, pH 8.5, 30℃, 0.05 mol/L Tris-HCl, 60 min. Under optimal conditions, the conversion of (±)-ethyl 2-chloropropinate could reach 49% and the optical purity (e.e.s) of product (R)-ethyl 2-chloropropinate could reach 98%. After comparing the kinetic resolutions of racemic methyl 2-chloropropionate and racemic ethyl 2-chloropropinate by esterase EST12-7, the chain length of the 2-chloropropionate esters could greatly affect the kinetic resolutions catalyzed by esterase EST12-7.