METABOLIC PRODUCTS OF MICROORGANISMS. 263

NIKKOMYCINS S_z, S_x, So_z and So_x, NEW INTERMEDIATES ASSOCIATED TO THE NIKKOMYCIN BIOSYNTHESIS OF Streptomyces tendae

Abstract

New intermediates associated with nikkomycin biosynthesis, called nikkomycins S_z, S_x, So_z and So_x, 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 S_z and S_x, 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.