Yan Hong-de, Wang Zhao, Chen Ling-jie
College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, People's Republic of China.
J Ind Microbiol Biotechnol. 2009 May;36(5):643-8. doi: 10.1007/s10295-009-0531-1. Epub 2009 Feb 11.
Kinetic resolution of alpha-lipoic acid, a case of remote stereocenter discrimination, was accomplished using lipase from Aspergillus oryzae WZ007. Performance of this lipase was investigated for enantioselective esterification of (S)-alpha-lipoic acid, leaving the target product (R)-alpha-lipoic acid in unreacted form. The effects of chain length of alcohol, type of solvent, molar ratio of alcohol:acid, and reaction temperature were studied. The optimum reaction conditions were found to be esterification with n-octanol at 50 degrees C in heptane with an alcohol:acid molar ratio of 5:1. The conversion rate of alpha-lipoic acid was 75.2%, with an enantiomeric excess of 92.5% towards unreacted substrate in a reaction time of 48 h.
使用米曲霉WZ007脂肪酶实现了α-硫辛酸的动力学拆分，这是一个远程立体中心识别的案例。研究了该脂肪酶对（S）-α-硫辛酸进行对映选择性酯化反应的性能，使目标产物（R）-α-硫辛酸以未反应的形式留存。研究了醇链长度、溶剂类型、醇与酸的摩尔比以及反应温度的影响。发现最佳反应条件是以正辛醇为酯化试剂，在庚烷中于50℃进行反应，醇与酸的摩尔比为5:1。在48小时的反应时间内，α-硫辛酸的转化率为75.2%，对未反应底物的对映体过量为92.5%。
