Abstract Analogs submitted by ethyl, n-propyl, n-butyl, and isopropyl groups instead of methyl group adjacent to a ketone group of acetohexamide were synthesized and the structural requirements of carbonyl reductase from rabbit kidney for these analogs were kinetically examined. The hydrophobicities in straight-chain alkyl groups of acetohexamide analogs were found to play an important role in the catalytic activity and substrate-binding ...