PRADIMICIN-S, A NEW PRADIMICIN ANALOG .3. APPLICATION OF THE FRIT-FABLC MS TECHNIQUE TO THE ELUCIDATION OF THE PRADIMICIN-S BIOSYNTHETIC-PATHWAY/

The biosynthetic pathway of pradimicin S (PRM-S) was investigated by u sing sinefungin and bioconversion experiments with aglycones of pradim icin A (PRM-A) and Actinomadura spinosa AA0851, a PRM-S producer. Addi tion of sinefungin to the strain inhibited the formation of 11-O-demet hyl-7-O-methylpradinone II (11dM-7M-PNII) as also determined to occur with its addition to the PRM-A producer. In feeding PRM-A aglycone and its analogs to the strain early in PRM-S biosynthesis, good identific ations of bioconverted products were obtained by frit-FAB LC/MS as fol lows: 11-O-demethylpradinone II (11dM-PNII), 11dM-7M-PNII, 11-O-demeth ylpradinone I (11dM-PNI), 11-O-demethylpradimicinone I (11wdM-PMNI) an d pradimicinone I (PMNI) were converted to PRM-S. Pradimicin B (PRM-B) and pradimicin L (PRM-L) were converted to PRMs-L and -S and PRM-S, r espectively. A biosynthetic pathway for PRM-S is proposed.