Microbial conversion of steffimycin and steffimycin B to 10-dihydrosteffimycin and 10-dihydrosteffimycin B

It has been shown that steffimycin (1) and steffmycin B (2) are reduced at the C-10 carbonyl by Actinoplanes utahensis, UC-5885 and Chaetomium sp., UC-4634, respectively. Using cell-free extracts of the latter organism, the optimum conversion time, pH, and enzyme concentration have been determined for the conversion of 2 to 4. The biochemical conversion of 2 has been found to be TPNH linked.