Enzymatic Strategies for Nitrogen–Nitrogen Bond Formation in Natural Product Biosynthesis

Nitrogen–nitrogen (N–N) bonds constitute essential structural motifs in numerous bioactive natural products and pharmaceuticals. Recent advances in genomics and biochemistry have unveiled diverse enzymatic strategies employed by nature to forge these chemically challenging linkages. This review highlights the discovery and mechanistic elucidation of key enzyme families responsible for N–N bond formation, including heme-dependent hydrazine synthases, zinc-dependent hydrazine synthetases, ATP-dependent diazotases or N -nitrosylases, and membrane-bound hydrazine synthases and diazotase. We summarize the biosynthetic pathways of representative N–N-containing natural products, emphasizing the catalytic logic and chemical ingenuity of these enzymes. Understanding these biological routes not only expands the enzymology of N–N bond formation but also provides a foundation for biocatalyst development and genome-driven discovery of novel bioactive compounds.