摘要
Chiral secondary alcohols with additional functional groups are frequently required as important and valuable synthons for pharmaceuticals, agricultural and other fine chemicals. With the advantages of environmentally benign reaction conditions, broad reaction scope, and high stereoselectivity, biocatalytic reduction of prochiral ketones of- fers significant potential in the synthesis of optically active alcohols. A CmCR homologous carbonyl reductase from Pichia guilliermondii NRRL Y-324 was successfully overexpressed. Substrate profile characterization revealed its broad substrate specificity, covering aryl ketones, aliphatic ketones and ketoesters. Furthermore, a variety of ketone substrates were asymmetrically reduced by the purified enzyme with an additionally NADPH regeneration system. The reduction system exhibited excellent enantioselectivity （~ 99% ee） in the reduction of all the aromatic ketones and ketoesters, except for 2-bromoacetophenone （93.5% ee）. Semi-preparative reduction of six ketones was achieved with high enantioselectivity （〉99% ee） and isolation yields （〉80%） within 12 h. This study provides a useful guidance for further application of this enzyme in the asymmetric synthesis of chiral alcohol enantiomers.
Chiral secondary alcohols with additional functional groups are frequently required as important and valuable synthons for pharmaceuticals, agricultural and other fine chemicals. With the advantages of environmentally benign reaction conditions, broad reaction scope, and high stereoselectivity, biocatalytic reduction of prochiral ketones of- fers significant potential in the synthesis of optically active alcohols. A CmCR homologous carbonyl reductase from Pichia guilliermondii NRRL Y-324 was successfully overexpressed. Substrate profile characterization revealed its broad substrate specificity, covering aryl ketones, aliphatic ketones and ketoesters. Furthermore, a variety of ketone substrates were asymmetrically reduced by the purified enzyme with an additionally NADPH regeneration system. The reduction system exhibited excellent enantioselectivity （~ 99% ee） in the reduction of all the aromatic ketones and ketoesters, except for 2-bromoacetophenone （93.5% ee）. Semi-preparative reduction of six ketones was achieved with high enantioselectivity （〉99% ee） and isolation yields （〉80%） within 12 h. This study provides a useful guidance for further application of this enzyme in the asymmetric synthesis of chiral alcohol enantiomers.
基金
This work was financially supported by the National Natural Science Foundation of China （No 21276082）, Ministry of Science and Technology, P. R. China （No.2011CB710800）, China National Special Fund for State Key Laboratory of Bioreactor Engineering （No. 2060204）.
