Highly enantioselective double reduction of phenylglyoxal to (R)-1-phenyl-1,2-ethanediol by one NADPH-dependent yeast carbonyl reductase with a broad substrate profile

The activity and enantioselectivity of a carbonyl reductase from Pichia pastoris GS115 were evaluated with a series of carbonyl compounds including aryl aldehydes, ketones, α- and β-ketoesters. This recombinant enzyme possessed a broad substrate profile with the ability of reducing both aldehydes and ketones. Especially, the enzyme catalyzed the double reduction of phenylglyoxal to (R)-1-phenyl-1,2-ethanediol with 99% yield and 99% ee by coupling with d-glucose dehydrogenase for the regeneration of cofactor NADPH, representing the first example of effective reduction of both aldehyde and ketone functional groups in one molecule by using only one enzyme. Furthermore, this study provides valuable information for guiding the future application of this versatile biocatalyst.