Terminal steps in the biosynthesis of herbicidins, nucleoside antibiotics.

The biosynthetic relationship of the herbicidins produced by Streptomyces saganonensis was studied with blocked mutants by means of a bioconversion method using growing and resting cells. It is proposed that the biosynthetic sequence for herbicidins is; herbicidin G----herbicidin F----herbicidin A. Both herbicidins A and F were converted to herbicidin B by non-enzymatic reactions. Herbicidin G was also converted to herbicidin C non-enzymatically.