Synthesis of H-3 and C-14-Sch 27899 by fermentation and evaluation of in vivo label stability

H-3 and C-14-Sch 27849 have been prepared by fermentation using the Micromo nospora carbonacea organism. In the case of H-3-Sch 27899, the label was in corporated by a single addition of 100 mCi of 70Ci/mmole L-[H-3-methyl]-met hionine to two flasks. For C-14-Sch 27899, 48 mCi of 55 mCi/mmole L-[C-14-m ethyl]-methionine was added in five aliquots to five flasks over a five day period. Both batches were isolated by solvent extraction, oxidized and pur ified by column chromatography and hplc. An overall incorporation of 7.8%, was found from L-[H-3-methyl]-methionine and 18.7% from L-[C-14-methyl]-met hionine. The in vivo stability of label of H-3 and C-14-Sch 27899 was deter mined, with 14C-Sch 27899 found to be a better choice for use in in vivo me tabolism studies.