| abstract |
Described is a process for producing a new FK-506 antagonist agent, a C-21 hydroxylated analog of FR-900520 under novel fermentation conditions utilizing the novel microorganism, Streptomyces hygroscopicus (Merck Culture Collection MA 6832) ATCC No. 55166. The macrolide antagonist is useful in preventing and/or counteracting accidental or inadvertent FK-506 overdosage in an FK-506 therapeutic program designed to prevent autoimmune diseases or human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants. |