摘要:
光学活性仲醇是合成多种生物活性化合物的原料和关键中间体,微生物细胞表面展示酶在生物催化和生物转化制备生化产品等方面表现出良好的应用性.研究了黑曲霉表面展示南极假丝酵母脂肪酶B(Candida antarctica li-pase B,CALB)制备的全细胞催化剂(AN-CALB)动力学拆分仲醇的催化性能.以2-辛醇作为反应底物,研究了酰基供体、2-辛醇与乙酸异丙烯酯物质的量比、AN-CALB添加量、水活度、温度及溶剂对AN-CALB催化2-辛醇拆分的影响,确定最优反应条件为:以乙酸异丙烯酯为酰基供体、2-辛醇与乙酸异丙烯酯物质的量比1: 1、AN-CALB添加量50 g·L-1、水活度0.11、温度45°C、以甲苯为溶剂,在此条件下,反应12 h的底物转化率达47.4%,eep值为99.6%,E值大于600.在最优反应条件下,AN-CALB对8种仲醇均表现出较好的拆分效果,底物转化率最高接近50%.该研究为仲醇动力学拆分提供了新的催化剂选择.%Optically active sec-alcohols are starting materials and key intermediates for the synthesis of many bioac-tive compounds.Enzymes displaying on the microbial cell surface show good applicability in biocatalysis and bioconver-sion of biochemical products.Consequently,we prepared whole-cell biocatalyst(AN-CALB) with surface displayed Can-dida antarctica lipase B(CALB) by Aspergillus niger,and studied the catalytic performance of AN-CALB to the kinetic resolution of sec-alcohols.Using 2-octanol as a model substrate,we investigated the effects of acyl donor,molar ratio of 2-octanol to isopropenyl acetate,AN-CALB addition,water activity,temperature,and solvent on the resolution ability of AN-CALB.The results show that the optimum reaction conditions are as follows:isopropenyl acetate as a acyl donor,the molar ratio of 2-octanol to isopropenyl acetate of 1: 1, the AN-CALB addition of 50 g·L-1,the water activity of 0.11,the temperature of 45 °C,and methylbenzene as a solvent.Under above conditions,the 2-octanol conversion rate is 47.4%,the eep value is 99. 6%,and the enantiomeric ratio E value is more than 600 in case of reacting for 12 h. AN-CALB shows good resolution effects to 8 kinds of sec-alcohols,and the substrate conversion rate reaches the highest of 50%. This study provides a new catalyst alternative for the kinetic resolution of sec-alcohols.