Ibrutinib is an anticancer drug targeting B-cell malignancies. The key chiral intermediate for ibrutinib synthesis is the alcohol (S)-N-Boc-3-hydroxypiperidine ((S)-NBHP), which can be produced via ketoreductase (KRED)-catalyzed bioreduction. After screening a small inventory of 27 KRED5 mined from the genome of Chryseobacterium sp. CA49, ChKRED03 was selected as the best performer, leading to the complete conversion of 100 g substrate/L within 10 h to yield (S)-NBHP with high enantiomeric excess ( >99% ee). The enzyme was NADPH dependent, and the highest enzymatic activity was observed at 30 degrees C in potassium phosphate buffer (pH 7.0). At a substrate/catalyst ratio of 66.7 (w/w), ChKRED03 catalyzed the complete conversion of 200 g/L substrate within 3 h to yield (S)-NBHP with >99% ee, demonstrating great potential for industrial application. (C) 2016 Elsevier Ltd. All rights reserved.