HERBOXIDIENE - A POTENT PHYTOTOXIC POLYKETIDE FROM STREPTOMYCES SP A7847

Investigation of a secondary metabolite produced by Streptomyces sp. A7847 (ATCC 49982) has resulted in the identification of herboxidiene (1, C25H42O6), a novel polyketide with exceptional phytotoxicity to several annual weed species. Synthetic modification studies have defined the permissible structural alternations of 1 which maintain biological activity. Significant structural change (see compounds 12 and 13) resulted in a loss of activity as did opening of the epoxide ring (we compounds 5-8) or oxidation of the secondary alcohol at carbon 18 (3).