Bisintercalator depsipeptides are a group of natural non-ribosomal peptides (NRPs) with a C2-symmetric macrocyclic scaffold. Due to the intricate architectural complexity and antitumor potency of these molecules, there has been of great interest in their total chemical synthesis, modes of action and biosynthesis. As a prototype of the decadepsipeptide class, luzopeptins displays very strong antitumor and antiviral activities. The rare acylsubstituted tetrahydropyridazine-3-carboxylic acid (Thp) subunits in their structures are critical to the biological activities. However, the biosynthetic mechanism of luzopeptins in nature has not been elucidated, therefore preventing the application of modern synthetic biology approaches to its structural innovation and structure-function relationship studies.

Recently, Prof. Yi-Ling Du and colleagues, from the Zhejiang University School of Medcine, revealed the biosynthetic machinery of luzopeptins in the soil actinomycetes Actinomadura luzonensis (Angew. Chem. Int. Ed. 2021, 60, 19821–19828). In this work, they reconstitute the complete enzymatic tailoring pathway in luzopeptin A biosynthesis through in vivo genetic and in vitro biochemical approaches. Significantly, we found a multitasking cytochrome P450 enzyme that catalyzes four consecutive oxidations including the highly unusual carbon–nitrogen bond desaturation. Moreover, they identified a membrane-bound acyltransferase that likely mediates the subsequent O-acetylation extracellularly, as a potential self-protective strategy for the producer strain. Further genome mining of novel decadepsipeptides and an associated P450 enzyme have provided mechanistic insights into the P450-mediated carbon–nitrogen bond desaturation. These results not only reveal the molecular basis of pharmacophore formation in bisintercalator decadepsipeptides, but also expand the catalytic versatility of P450 family enzymes.