The Fate of Molecular Oxygen in Azinomycin Biosynthesis.

The azinomycins are a family of aziridine-containing antitumor antibiotics and represent a treasure trove of biosynthetic reactions. The formation of the azabicyclo[3.1.0]hexane ring and functionalization of this ring system remain the least understood aspects of the pathway. This study reports the incorporation of O-18-labeled molecular oxygen in azinomycin biosynthesis including both oxygens of the diol that ultimately adorn the aziridino[1,2-a]pyrrolidine moiety. Likewise, two other sites of heavy atom incorporation are observed.