Metabolic products of microorganisms. 263. Nikkomycins SZ, SX, SoZ and SoX, new intermediates associated to the nikkomycin biosynthesis of Streptomyces tendae.

New intermediates associated with nikkomycin biosynthesis, called nikkomycins SZ, SX, SoZ and SoX, were isolated and characterized from the culture broth of Streptomyces tendae Tü 901/S 2566. They are analogues to octosyl acids, shunt metabolites of polyoxin biosynthesis. The decreasing amounts of nikkomycins SZ and SX, produced in the culture medium, shows a significant correlation to the increasing amounts of the biologically active nikkomycins Z and X, dependent on the increasing concentration of iron.