Abstract: Microbial transformation of a macrolide immunosuppressant by the microorganism Streptomyces sp., (Merck Culture Collection MA 6960) ATCC No. 55387 yields a compound of the structural formula (I): ##STR1## This compound is an immunosuppressant useful in a mammalian host for the treatment of autoimmune diseases, infectious diseases, the prevention of rejection of foreign organ transplants and/or related afflictions, diseases and illnesses.

Abstract: Described is a new enzyme, 31-O-desmethyl-FK-506 O-methyltransferase (FKMT) and its N-terminal amino acid sequence. This enzyme can specifically and preferentially methylate the C-31 hydroxy group in 31-O-desmethyl FK-506/FR-900506 and other 31-O-desmethyl analogs of FK-506/FR-900506 and related compounds such as 31-O-desmethyl immunomycin type molecules, also designated FK-520 and FR-900520 by Fujisawa. The enzyme can be isolated from a FK-506 producing microorganism Streptomyces sp. (Merck Culture Collection No. MA 6858) ATCC No. 55098. Employing the enzyme in its active form, supplemented with Mg.sup.+2 ion, in the presence of the methyl donor, S-adenosyl methionine (SAM), derivatives of 31-O-desmethyl FK-506, 31-O-desmethyl FK-520 and related 31-O-desmethyl compounds may be prepared.

Abstract: Described is a process for producing a new immunosuppressant, a C-31 desmethyl, C-19/C-22 cyclic hemiketal biotransformation analog (Compound I) of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces, lavendulae ATCC No. 55209. Also disclosed is the C-31 methylated devivative (Compound II) of Compound I produced by enzymatic methylation using 31-O-desmethylimmunomycin O-methyl transferase, (DIMT), a methyl transferase enzyme. The macrolide immunosuppressants are useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: Tissue cultures of cells from seed heads of Papaver bracteatum Lindl, Population Arya II, are grown in artificial nutrient media to produce thebaine which is then extracted therefrom. An example of an artificial nutrient medium used for the tissue culture is revised tobacco medium supplemented with 1% agar and 1ppm 2,4-dichlorophenoxyacetic acid.