文献类型：期刊文献

中文题名：水对脂肪酶非水相催化拆分2-辛醇的影响

英文题名：EFFECT OF WATER ON CATALYTIC RESOLUTION OF 2OCTANOLBY LIPASE IN NONAQUEOUS MEDIA

作者：朱洁[1,2,3];刘洪湖[1,2,3];许建和[1,2,3];曹淑桂[1,2,3];胡英[1,2,3]

机构：[1]华东理工大学化学系;[2]华东理工大学生物反应器工程国家重点实验室;[3]吉林大学酶工程国家重点实验室

年份：1998

卷号：19

期号：3

起止页码：255

中文期刊名：催化学报

收录：CSTPCD;;Scopus;北大核心:【北大核心1996】；CSCD:【CSCD2011_2012】；

基金：吉林大学酶工程国家重点实验室开放研究课题

语种：中文

中文关键词：脂肪酶;辛醇;拆分;水;手性分离;辛醇;酯化

外文关键词：Lipase, Nonaqueous catalysis, 2octanol, Kinetic resolution, Effect of water

摘要：利用假单胞菌脂肪酶在有机溶剂中催化的对映选择性酯化反应，对外消旋（Ｒ，Ｓ）－２－辛醇进行了动力学拆分，考察了水对脂肪酶非水相催化性能的影响．结果表明，酶在有机溶剂中的活力显著依赖于系统的加水量，二者呈钟罩形曲线，但最佳加水量范围以及酶的活力大小因溶剂不同而异；在最佳加水量范围内，系统含水量的变化对酶的对映选择性影响不大，但加水量增大（＞１％，Ｖ／Ｖ）会导致逆反应（酯的水解）加剧而降低醇的光学纯度；在反应进行一定时间后，添加分子筛移走酯化反应生成的水，可显著提高反应的转化率，并增大醇的对映体过量，但当超过快反应（Ｒ－醇的酯化）的平衡转化率时，反而会造成残留醇的光学纯度下降．用二甲基甲酰胺和乙二醇取代部分或全部的水添加于非水相酶反应系统，也能起到与水类似的甚至更强的激活酶的作用．
Racemic (R,S)2octanol was kinetically resolved through enantioselective esterification catalyzed by Pseudomonas sp. lipase in organic solvents and the effect of water on catalytic performance of lipase in nonaqueous media was examined. It was demonstrated that the activity of enzyme in organic solvents depended remarkably on the amount of water added to the system, observing a belltype curve, though the optimum amount of water addition and the enzyme activity differed in different organic media. Within the optimum range of water addition, the amount of water does not affect enantioselectivity of the emzyme significantly, but rather low enantiomeric excess of (S)alcohol was observed when too much water (>1%, V/V) was added to the system, possibly due to the enhancement of the reversed reaction (hydrolysis of the ester formed). Conversion of the 2octanol and also the enantiomeric excess of (S)alcohol could be considerably improved by adding molecular sieves after a certain period of reaction to remove the water generated in esterification. Once the fast reaction (esterification of (R)alcohol) reaches its equilibrium (XR=971%), further reaction will result in a sharp decrease in the optical purity of residual alcohol. When a little amount of N,Ndimethylformamide (DMF) or glycol was added to the nonaqueous media to replace part or all of water, the enzyme could be activated to a similar or even more remarkable level as compared with water.