酵母细胞不对称还原4-氯苯乙酮合成相应手性醇

以4-氯苯乙酮(C l-ACP)为苯环上含卤素的芳香酮的模型底物,研究了活性酵母细胞在水相体系中催化该类芳香酮不对称还原合成相应手性醇的反应特性。结果表明,酵母细胞可催化C l-ACP的不对称还原反应,产物为S-型的4-氯-α-苯乙醇(C l-PEA),反应的立体选择性很高,S-C l-PEA的e.e.值可达到99%左右。较合适的反应条件为:反应60 h,底物浓度低于20 mmol/L,体系的pH为6~8,温度为30℃左右,酵母细胞用量为20 g/L左右,以质量浓度为20 g/L的葡萄糖为辅助底物。产物得率可达到33%。同时发现酵母细胞可以选择性地氧化外消旋C l-PEA中的S-型醇为C l-ACP。

Asymmetric Reduction of 4-Chloroacetophenone to Corresponding Chiral Alcoho Catalyzed by Saccharomyces cerevisiae

Optically active halogen-containing aryl alcohols are one kind of the most important chiral building blocks for many single enantiomer pharmaceuticals.Asymmetric reduction of prochiral ketone to these chiral alcohols by active microbe cells is one of the most promising routes.The asymmetric reduction of 4-chloroacetophenone(Cl-ACP) to its corresponding chiral alcohol(4chloro-α-phenylethyl alcohol,Cl-PEA) in aqueous phase catalyzed by Saccharomyces cerevisiae was chosen as the model reaction.Experimental result showed that Cl-ACP could be reduced to S-Cl-PEA with excellent stereoselectivity.The e.e.of S-Cl-PEA could reach as high as 99%.The appropriate conditions for this reaction were 60 h reaction time,Cl-ACP under 20 mmol/L,pH 6.0~8.0,30 ℃,20 g/L cells and with 20 g/L glucose as the cosubstrate.The yield of Cl-PEA could reach 33%.It was also found that S-Cl-PEA could be selectively oxidized to Cl-ACP by Saccharomyces cerevisiae.