Efficient enantioselective hydrolysis of D,L-phenylglycine methyl ester catalyzed by immobilized Candida antarctica lipase B in ionic liquid containing systems
Efficient enantioselective hydrolysis of D,L-phenylglycine methyl ester catalyzed by immobilized Candida antarctica lipase B in ionic liquid containing systems
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DOI：
10.1016/j.jbiotec.2006.01.017
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发表时间：
2006-08-20
影响因子：
4.1
通讯作者：
Wang, Ju-Fang
中科院分区：
文献类型：
--
作者：
Lou, Wen-Yong;Zong, Min-Hua;Wang, Ju-Fang
在离子液体中，固定化南极假丝酵母脂肪酶B（Novozym 435）催化D，L-苯甘氨酸甲酯对映体选择性水解制备了对映体纯的D-苯甘氨酸。Novozym 435在含有IL（BMIMBF 4）-B-的体系中表现出优异的活性和对映体选择性。与测试的几种典型有机溶剂相比。已经发现，离子液体的阳离子，特别是阴离子对反应具有显著的影响，并且离子液体（BMIMBF 4）-B-，在所考察的各种离子液体中，最适合于该反应，具有最高的初始速率和对映选择性。在（BMIMHSO_4）-H ~-存在下，反应的活性和对映选择性大大降低.此外，注意到酶促水解强烈依赖于（BMIMBF 4）-B-。共溶剂体系中IL的最佳含量为20%（v/v）。在测定的四种共溶剂和磷酸盐缓冲液中，最低的表观K。在20%（v/v）（BMIMBF 4）-B-存在下，反应的最大反应速率达到最大值。与磷酸盐缓冲液的共溶剂。此外，还研究了各种影响变量。最适pH值为8.0，底物浓度为80 mM，反应温度为25-30 ℃，振荡速度为150 rpm。对映体选择性分别为2.46 mM/min、93.8%（底物转化率为53.0%）和38。当水解在减压下进行时，初始速率（2.64 mM/min）和对映选择性（E = 43）得到提高。(c)2006 Elsevier B. V.保留所有权利。
Immobilized Candida antarctica lipase B (Novozym 435)-catalyzed enantioselective hydrolysis Of D,L-phenylglycine methyl ester to enatiopure D-phenylglycine was successfully conducted in the systems with ionic liquids (ILs). Novozym 435 exhibited excellent activity and enantioselectivity in the system containing the IL (BMIMBF4)-B-. compared to several typical organic solvents tested. It has been found that the cations and, particularly, the anions of ILs have a significant effect on the reaction, and the IL (BMIMBF4)-B-., which shows to be the most suitable for the reaction, gave the highest initial rate and enantioselectivity among various ILs examined. The reaction became much less active and enantioselective in the systems with (BMIMHSO4)-H-.. Also, it was noticed that the enzymatic hydrolysis was strongly dependent on (BMIMBF4)-B-. content in the co-solvent systems and the favorable content of the IL was 20% (v/v). Of the assayed four co-solvents and phosphate buffer, the lowest apparent K. and activation energy, and the highest V-max of the reaction were achieved using 20% (v/v) (BMIMBF4)-B-. co-solvent with phosphate buffer. Additionally, various influential variables were investigated. The optimum pH, substrate concentration, reaction temperature and shaking rate were 8.0, 80 mM, 25-30 degrees C and 150 rpm, respectively, under which the initial rate, the residual substrate e.e. and the enantioselectivity were 2.46 mM/min, 93.8% (at substrate conversion of 53.0%) and 38, respectively. When the hydrolysis was performed under reduced pressure, the initial rate (2.64 mM/min) and the enantioselectivity (E = 43) were boosted. (c) 2006 Elsevier B.V. All rights reserved.