Peniandranoids A-E: Meroterpenoids with Antiviral and Immunosuppressive Activity from a Penicillium sp.

Peniandranoids A-E (-), five new meroterpenoids, together with three known analogues (-), were isolated from the fermentation of a soil-derived fungus, sp.sb62. Their structures including absolute configurations were determined by extensive spectroscopic analysis, and the absolute configurations of compounds and were further elucidated by single-crystal X-ray diffraction. Peniandranoids A-E belong to a rare class of andrastin-type meroterpenoids incorporating an extra polyketide unit (a C polyketide unit for and , a C polyketide unit for and , and a furancarboxylic acid unit for ). Compounds and exhibited favorable inhibitory activities against influenza virus A (H1N1) with EC values of 19 and 14 μg/mL, respectively. Compounds - exhibited potent immunosuppressive activities against concanavalin A-induced T cell proliferation with EC values ranging from 4.3 to 27 μM and lipopolysaccharide-induced B cell proliferation with EC values ranging from 7.5 to 23 μM, respectively.