Microbial conversion of saframycin A to 25-dihydrosaframycin A and 21-decyano-25-dihydrosaframycin A (25-dihydrosaframycin B) and their biological activities.

Abstract
25-Dihydrosaframycin A(AR1) and 21-decyano-25-dihydrosaframycin A(AR3) were produced by the microbial conversion of saframycin A(SA). Efficient conversion of SA to AR1 and AR3 was observed with Rhodococcus amidophilus IFM 144. Though the antimicrobial activity [against bacteria and fungi] of AR1 was 1/10 that of SA, the in vitro antitumor activity [against mouse leukemia] of AR1 was equivalent to that of SA; AR3 was biologically less active.