脂肪酶催化酯化拆分与水解拆分2-甲基丁酸及其酯  

Kinetic Resolution of 2-Methylbutyric Acid and Its Ester by Esterification and Hydrolysis with Lipases

作　　者：李小路[1] 王栋[1] 徐岩 耿亚维[1] 陈聪[1] 王楠[1] 

机构地区：[1]江南大学生物工程学院工业生物技术教育部重点实验室,江苏无锡214122

出　　处：《催化学报》2009年第9期951-957,共7页

基　　金：国家高科技发展计划(863计划;2007AA100401);江苏省自然科学基金(BK2007020);生物反应器工程国家重点实验室开放课题

摘　　要：2-甲基丁酸手性中心碳原子上的基团差异较小,是一种典型的酶法动力学拆分较为困难的风味化合物.本文分别在不同体系中比较了几种商品化脂肪酶和华根霉脂肪酶(RCL)催化酯化和水解反应对2-甲基丁酸及其酯的拆分,结果表明,RCL不仅在非水相中具有一定的选择性酯化能力,而且在水相中具有更强的选择性水解2-甲基丁酸乙酯的能力,在40oC下优先水解(S)-型底物,反应10h后(R)-2-甲基丁酸乙酯的ee值为92.4%.进一步考察了温度对RCL催化酯化拆分与水解拆分的影响,结果表明,低温下反应的对映体选择性较高,在4oC下通过水解拆分获得的(R)-2-甲基丁酸乙酯的ee值可提高至95.0%.The resolution of 2-methylbutyric acid, one of the typical flavor compounds, is difficult by the enzymatic kinetic method because the steric differences between the methyl and ethyl groups attached to its chiral carbon atom are too small to allow efficient stereochemical recognition by enzyme. The capacity of some commercial lipases and a lipase from Rhizopus chinensis （RCL） to catalyze enantioselective esterification and enantioselective hydrolysis of 2-methylbutyric acid and its ester in different systems was investigated. The results showed that, RCL not only had a certain esterification enantioselectivity in non-aqueous media but also had higher hydrolysis enantioselectivity in aqueous phase. The ee value of 92.4% of （R）-ethyl 2-methylbutyrate was obtained after 10 h hydrolysis reaction. Furthermore, the influence of temperature on the esterification and hydrolysis resolution catalyzed by RCL was investigated. A higher enantioselectivity was obtained at 4 ℃, and the ee value of （R）-ethyl 2-methylbutyrate from hydrolysis resolution was increased to 95.0% at 4 ℃.

关 键 词：华根霉脂肪酶 选择性酯化 选择性水解 动力学拆分 2-甲基丁酸 2-甲基丁酸乙酯 

分 类 号：O621.25[理学—有机化学]