Studies on mycotrienin antibiotics, a novel class of ansamycins. II. Structure elucidation and biosynthesis of mycotrienins I and II.

Abstract
The structures of mycotrienins I and II were determined mainly by their NMR spectral analysis. Mycotrienins are unique ansamycin antibiotics containing a 21-membered macrocyclic lactam ring and a cyclohexylcarbonyl moiety. The labeling experiments with sodium [1-13C]acetate and sodium [1-13C]propionate revealed that 6 acetate units and 2 propionate units were incorporated into the molecule of mycotrienin I [by Streptomyces rishiriensis].