Enhancement of Candida parapsilosis catalyzing deracemization of (R,S)-1-phenyl-1,2-ethanediol to its (S)-enantiomer by a highly productive “two-in-one” resin-based in situ product removal strategy

In this study, a highly efficient process for Candida parapsilosis-catalyzed deracemization of racemic 1-phenyl-1,2-ethanediol (PED) was described, based on a resin-based in situ substrate feeding and product removal (ISSFPR) methodology. The resin H103 was selected and used to keep the combined concentration of (R)-PED and (S)-PED at about 15 g/l in aqueous phase. In the presence of 143 g/l H103 resin, 50 g/l of racemic substrate was converted to (S)-PED with 99.3% enantiomeric excess (ee) in 92% yield, while the initial reaction could afford an ee > 99% only when the substrate concentration was 15 g/l or lower. To our knowledge, this was the first report on the application of a resin-based ISSFPR technique for enhancing the efficiency of microbial stereoinversion.