摘要
采用苯乙酮为模式底物,选用了3种典型的离子液体作为反应介质系统研究了离子液体与缓冲液构成的均相及两相体系中固定化光合细菌催化不对称还原反应的特性.通过对构建的离子液体反应体系进行条件优化,发现与水相及有机相相比,离子液体作为生物催化反应介质更有利于还原反应的进行,并且离子液体及固定化细胞易回收重复利用.研究结果表明,在含15%体积分数的亲水性离子液体[EMIM][EtSO4]/缓冲液反应体系中,当底物苯乙酮浓度为35 mmol/L时,在最佳的反应条件下,催化生成的产物主要是S-苯乙醇,产率和对映值分别达到82.7%和99.9%.离子液体不仅提高了催化反应速率,而且增加了固定化光合细菌的稳定性,为反应介质和生物催化剂的循环使用提供了保证.
Acetophenone was selected as the model substrate, and monophasic and biphasic ionic liquid/buffer reaction systems were built respectively through three typical ionic liquids. The systematic study to the reaction characteristics of immobilized photosynthetic bacteria has been inuestigated. Based on optimization of reaction conditions and systems, we found that the use of ionic liquids instead of conventional solvents give better results than aqueous phase and organic phase systems. Furthermore, ionic liquids and immobilized cells can be recycled. The results indicate that immobilized photosynthetic bacteria can catalyze acetophenone to product corresponding （S）-phenylethanol mainly under the optimised conditions, such as in hydrophilic ionic liquid [ EMIM ] [ EtSO4 ] with 15 % volume fraction as monophasic ionic liquid/buffer reaction system. The yield and the enantiomeric excess values （ee） of （S）-phenylethanol were 82.7% and up to 99%, respectively. Ionic liquids not only enhance the catalytic reaction rate, but also increase the stability of biocatalysts. The reaction medium can be recycled and improve environmental friendiness of the systems.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2011年第5期427-434,共8页
Journal of Molecular Catalysis(China)
基金
山西省催化技术平台建设(2008091001)
关键词
离子液体
固定化光合细菌
不对称还原
苯乙酮
ionic liquids
immobilized photosynthetic bacteria
asymmetric reduction
acetophenone
