离子液体对固定化Saccharomyces cerevisiae细胞催化乙酰基三甲基硅烷不对称还原反应的影响

Effect of ionic liquid on asymmetric reduction of acetyltrimethylsilane catalyzed by immobilized Saccharomyces cerevisiae cells

对比研究了C4MIm.BF4-缓冲液混合体系和缓冲液单相体系中固定化面包酵母Saccharomyces cerevisiae细胞催化乙酰基三甲基硅烷不对称还原反应的特性,系统探讨了离子液体C4MIm.BF4对该反应的初速度、最大转化率和产物对映体纯度的影响规律。在各自最优的反应条件下,固定化面包酵母细胞在缓冲液单相体系中催化乙酰基三甲基硅烷不对称还原反应的初速度、最大转化率及产物e.e.值分别为84.8 mmol/(L.h)、99.2%和≥99.9%;而在C4MIm.BF4-缓冲液混合体系中,该反应的初速度、最大转化率及产物e.e.值分别为87.0 mmol/(L.h)、99.0%和≥99.9%。离子液体的存在,提高了固定化面包酵母细胞催化该反应的速度,但降低了固定化酵母细胞的操作稳定性。

Asymmetric reduction of acetyhrimethylsilane （ATMS） catalyzed by immobilized baker＇s yeast （Saccharomyces cerevisiae） cells in Tris buffer-C4MIm·BF4 co-solvent system and in Tris buffer monophasic system was comparatively studied. The effect of IL on the initial reaction rate, maximum conversion and product e. e. of the bioreduction was systematically explored. Under the optimum conditions in each medium, the initial reaction rate, maximum conversion and product e.e. were 84.8 mmol/L· h, 99.2 % and ≥99.9 %, respectively, in Tris buffer monophasic system, while those in Tris buffer-C4 MIm· BF4 co-solvent system were 87.0 mmol/L· h, 99.0% and ≥99.9%, respectively. The presence of IL in the reaction system could enhance the reaction rate, but decrease the operational stability of immobilized yeast cells.