| abstract |
Described is a process for producing a new immunosuppressant, a C-19/C-22 cyclic hemiketal (Compound I) biotransformation analog of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces sp. (Merck Culture Collection MA6969) ATCC No. 55280. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants. |