MICROBIAL TRANSFORMATION OF DIHYDROSARSASAPOGENIN WITH MYCOBACTERIUM SP

Microbial transformation of sarsasapogenin (1) with Mycobacterium sp. (NRRL B-3805) gave 25(S)-neospirost-4-en-3-one (2) as the sole product in 62% yield. Incubation of dihydrosarsasapogenin (3) led to the isol ation of seven products in 0.5 (4), 6.6 (5), 5 (6), 16 (7), 1 (8), 1 ( 9), and 4.5% (10) yields,respectively, while 15% of 3 was recovered. A mong these products, 8 and 9 were C-22 steroids, and 10 was a C-19 ste roid. Isolation of these C-19 and C-22 steroids indicated that this mi croorganism is capable of cleaving the ether linkage between C-16 and C-22 in 3. In addition, l2 alpha-hydroxylation was also observed in al l these three metabolites.