A new vetivane-type sesquiterpenoid with a tricyclic 7/5/5 scaffold from the endophytic fungus <i>Penicillium oxalicum</i> 2021CDF-3

Natural sesquiterpenoids possess a variety of skeleton types with intriguing biomedical activities. In this study, a comprehensive chemical study of the endophytic fungus Penicillium oxalicum 2021CDF-3 yielded a new sesquiterpenoid, namely penicivetivane A (1). The chemical structure for 1 was thoroughly ascertained by using HRESIMS and NMR spectroscopic analyses, while the stereochemistry of 1 was further verified by X-ray diffraction analyses. 1 represented a rare natural vetivane-type sesquiterpenoid with a tricyclic 7/5/5 scaffold. Penicivetivane A (1) displayed strong antimicrobial properties against human pathogens Escherichia coli and Staphylococcus aureus, with respective MICs of 4 and 2 μg/mL. This study provided a new vetivane-type sesquiterpenoid with a lead potency for the discovery of anti-infective drugs.