A new cytosine glycoside from Streptomyces griseochromogenes produced by the use in vivo of enzyme inhibitors.

The identification of new cytosine glycosides and intermediates in the biosynthetic pathway of the antifungal antibiotic blasticidin S (1) was investigated using in vivo enzyme inhibition. Fermentations of Streptomyces griseochromogenes, the organism that produces 1, supplemented with the arginine analogue argininic acid or the argininosuccinate synthase inhibitor 2-methylaspartic acid were found to produce a new metabolite (7).