Multifunctional Cytochrome P450 Orchestrates Radical Cleavage and Non-radical Cyclization in 5-Oxaindolizidine Biosynthesis

Penicilactam A, a fungal alkaloid with a rare 5-oxaindolizidine scaffold, has remained uncharacterized in terms of its biosynthesis despite advances in microbial genomics. The researchers used retro-biosynthetic analysis of Penicillium citrinum HDN11-186 to investigate the biosynthesis of Penicilactam A. This study aimed to elucidate the biosynthetic pathway of Penicilactam A, which has long been elusive.