水/有机溶剂双相中固定化啤酒酵母细胞催化有机硅酮不对称还原

Asymmetric Microbial Reduction of Organosilyl Ketone with Immobilized Saccharomyces cerevisiae Cells in Water/organic Solvent Biphase System

研究了水 有机溶剂双相中 ,固定化啤酒酵母细胞催化三甲基硅乙酮不对称还原成 (- ) 1 三甲基硅乙醇的反应 ,系统探讨了振荡速度、有机溶剂疏水性、水相与有机溶剂相体积比、水相pH值和反应温度对反应速度、产率和产物光学纯度的影响 .结果表明 ,上述因素对固定化啤酒酵母细胞催化三甲基硅乙酮不对称还原反应均有较显著的影响 .正己烷为该反应最好的有机溶剂 ,振荡速度以 15 0r min为宜 ,水相与有机溶剂相体积比以1∶2较佳 ,适宜的 pH值为 8,最佳反应温度为 2 5～ 30℃ .在该优化反应条件下 ,反应最大产率和产物的光学纯度分别高达 96 8%和 95 7% (ee) .

Asymmetric microbial reduction of acetyltrimethylsilane to (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphase system was studied. The effects of shake speed, the hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric purity of the product were systematically explored. All the factors mentioned above have important effects on the reaction. n-Hexane is found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH and reaction temperature are 150 r/min, 1/2, 8 and 25similar to30degreesC respectively for the reaction, under which the maximum yield and enantiomeric purity of the product are as high as 96.8% and 95.7% (ee) respectively.