Recent advance in the biosynthesis of nitrogen-nitrogen bond-containing natural products

Nitrogen-nitrogen (N-N) bond-containing compounds are occasionally described in nature. Despite their interesting structural and biological features, biosynthetic machineries of N-N bond formation in nature remained undiscovered for a long time. However, the understanding on biosynthetic machineries of N-N bond formation have rapidly accumulated within the last few years. This includes the discovery of nitrous acid biosynthetic pathway used in secondary metabolism and the identification of metalloenzymes actually catalyzing N-N bond formation. In this review, we summarize the recent advances in the understanding on the biosyntheses of N-N bond-containing natural products.