Formation of amphetamine from its nitro analogue by anaerobic intestinal bacteria.

1. Microbial reduction of 1-phenyl-2-nitropropane 1 was carried out using 40 strains of intestinal anaerobic bacteria. Among them, 12 strains (Mitsuokella multiacidus, Clostridium perfringens, C. innocuum, C. clostiriiforme, C. difficile, C. butyricum, C. sp., Eubacterium limosum, E. aerofaciens, E. multiforme, Peptostreptococcus anaerobius and P. productus) had the ability to reduce 1 to amphetamine 2 (0.1-1% yield). 2. Clostridium species were more active than another intestinal anaerobic bacteria. 3. When Clostridium perfringens was used in preparative fermentation, the yield of 2 was increased, and its absolute structure had an (S)-configuration with an optical purity of 68% in enantiomeric excess.