Accumulation of an <i>E</i> , <i>E</i> , <i>E</i> ‐Triene by the Monensin‐Producing Polyketide Synthase when Oxidative Cyclization is Blocked

Abstract

Evidence for the intermediate in the polyether biosynthesis of the ionophore antibiotic monensin A has been obtained. A tridecaketide E,E,E-triene (see formula) has been isolated by using mutant strains of Streptomyces cinnamonensis. Characterization of this intermediate allows the likely biosynthetic route to monensin to be discriminated.