DMOA-derived polycyclic meroterpenoids with antiviral activities from the deep-sea-derived fungus Penicillium pancosmium A6A.

Two undescribed 3,5-dimethylorsellinic acid (DMOA) derived meroterpenoids, namely pancosterpenoids A (1) and B (2), were discovered from the EtOAc extract of the deep-sea sediment-derived fungus Penicillium pancosmium A6A. The gross structures were established by detailed analysis of the spectroscopic data (NMR and HRESIMS spectra), while their absolute configurations were resolved by comparing the experimental and calculated ECD data as well as X-ray single crystal diffraction analysis. Pancosterpenoid A (1) was the first representative of DMOA-derived meroterpenoids possessing a 6/6/6/5/5 pentacyclic system, while pancosterpenoid B (2) belongs to a class of rare 13-nor-citreohybridone meroterpenoids. Two metabolites were evaluated the antiviral effects against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) trVLP pseudovirus. As a result, compounds 1 and 2 showed moderately inhibitory activities with IC 50 values of 22.37 and 18.12 μM, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]