固定化脂肪酶催化(R,S)-1-苯乙醇转酯化拆分反应及动力学研究

摘要

利用制备的合Fe3O4无机磁性复合物FSN固定假单胞菌脂肪酶(Pseudomonas sp Lipase,PSL),获得具有高活性、高对映体选择性和易分离的固定化酶PSL/FSN.乙酸乙烯酯做酰化试剂,PSL/FSN在正庚烷溶剂中催化(R,S)-1-苯乙醇转酯化拆分反应,40℃反应2h时,(S)-1-苯乙醇对映体过量值ees和(R)-乙酸-1-苯乙酯的对映体过量值ecp均为99％,(R,S)-1-苯乙醇的转化率达到理论值.固定化酶PSL/FSN在70℃经2h热处理,其活性和对映选择性没有明显的下降；PSL/FSN重复使用10次,其活性和对映体选择性未出现衰减.基于实验数据,研究了固定化酶催化(R,S)-1-苯乙醇转酯化拆分反应的动力学行为,获得了(R,S)-1-苯乙醇转酯化拆分反应的动力学方程.%The Pseudomonas sp Lipase (PSD was immobilized on the inorganic magnetic compound support (FSN) containing nanoparticles Fe3O4. The immobilized lipase (PSL/FSN) has higher activity, conversion enantioselectivity and easier recovery advantages comparing with free lipase. PSL/FSN was used in the transesterification resolution of (R,S)-1-phenylethanol. The most suitable acyl donor, organic solvent and reaction temperature was vinyl acetate, respectively, refine n-heptane and 40 ℃. Under these conditions, the ee values of the substrate (S)-1-phenylethanol and the product ?-l- phenylethyl acetate were both 99% when reaction time is 2 h. After PSL/FSN was incubated 2 hours at 70 ℃ , its activity and enantioselectivity was not significantly reduced. The catalytic performance of PSL/FSN was not decreased after PSL/FSN was reused for 10 times. Based on experiment data of transesterification resolution of (R, S)-1-phenylethanol over immobilized lipase reaction, we have investigated its kinetic behavior and got its kinetic equation.