Penicichrysol A: an unprecedented polyketide produced by Penicillium chrysogenum

Abstract

Penicichrysol A (1), a highly oxygenated polyketide with an unprecedented skeleton, uniquely defined by multiple contiguous quaternary carbons, was isolated as a racemate from an endophytic fungus Penicillium chrysogenum that was sourced from the bulbs of the medicinal plant Lycoris radiata. Besides, three known biosynthetically related metabolites 2–4 were also obtained. The structure including the configuration of 1 was established via a combination of NMR spectroscopy and single-crystal X-ray diffraction analysis. A plausible biosynthetic pathway involving intriguing radical coupling and hemiketal reactions as key chemical transformations has been proposed.