Stereoselective bioreduction of ethyl 3-oxo-3-(2-thienyl) propanoateusing theshort-chain dehydrogenase/reductaseChKRED12

Ethyl ( S )-3-hydroxy-3-(2-thienyl)propanoate(( S )-HEES)acts as a key chiral intermediate for the blockbuster antidepressant drug duloxetine, which canbe achieved viathe stereoselective bioreduction ofethyl 3-oxo-3-(2-thienyl) propanoate (KEES) that containsa 3-oxoacyl structure.The sequences of the short-chain dehydrogenase/reductases from Chryseobacterium sp. CA49 were analyzed, and the putative3-oxoacyl-acyl-carrier-protein reductase, Ch KRED12, was able to stereoselectivelycatalyze theNADPH-dependent reduction to produce ( S )-HEES.The reductase activity of Ch KRED12 towardsothersubstrates with 3-oxoacyl structure were confirmed with excellent stereoselectivity (>99% enantiomeric excess) in most cases. When coupled with a cofactor recycling system using glucose dehydrogenase, the Ch KRED12 was able to catalyze the complete conversion of 100 g/l KEES within 12h, yielding the enantiopure product with >99% ee, showing a remarkable potential to produce ( S )-HEES.