A role for paxilline in the biosynthesis of indole–diterpenoid penitrem mycotoxins

[14C] Paxilline was biosynthetically incorporated into penitrem A (3.1–8.7%), and when calculated to include penitrem E to a greater extent (3.3–17%), in submerged fermentations of Penicillium janczewskii; concurrent biotransformation of [14C] paxilline to a hydroxy derivative may indicate another intermediate in penitrem biosynthesis.