疏水离子液体中生物不对称还原制备手性醇

摘要

Whole cells of Candida parapsilosis catalyze asymmetric reduction of 2⁃hydroxyacetophenone for preparation of optically pure ( R)⁃1⁃phenyl⁃1,2⁃ethanediol. The multiphase extraction of bioconversion was applied to improve substrate concentration,yield and the mass balance of the asymmetric reduction reaction . Different non⁃aqueous reaction systems were compared and aqueous/hydrophobicity ionic liquids ( ILs ) 1⁃butyl⁃3⁃ethylimidazolium hexafluorophosphate ( [ BEIM] PF6 ) biphasic system shown better biocompatibility and high mass balance. The effects of the different co⁃substrates, co⁃substrate mass, substrate concentration, catalyst mass, ILs ratio, pH value and reaction temperature on the biological catalysis reaction were studied. Reaction conditions of asymmetric reduction of 2⁃hydroxyacetophenone was optimized by orthogonal experimental design and response surface experimental design. Under the optimized reaction conditions,product concentration,yield and mass balance reached 15�35 g/L,76�8%, 84�3%,respectively�The enantiomeric excess(e.e.) value of product was above 99�9%.%针对近平滑假丝酵母全细胞不对称还原2羟基苯乙酮制备光学纯（ R）苯基乙二醇反应中底物的质量浓度、产量及质量平衡低的问题，运用多相萃取生物转化的原理，比较不同非水介质对不对称还原反应效率的影响，构建具有良好生物相容性和高质量平衡的水／疏水离子液体1丁基3乙基咪唑六氟磷酸盐（[ BEIM] PF6）双相反应体系。考察该体系下辅助底物种类、辅助底物用量、底物质量浓度、催化剂用量、离子液体比例、pH和反应温度对生物催化反应的影响，通过正交试验设计和响应面法优化不对称还原2羟基苯乙酮的反应条件，在最优反应条件下，产物质量浓度、产率和质量平衡得率分别达到15�35 g／L、76�8％和84�3％，产物的对映消旋值（ e． e．值）大于99�9％。