3,5-Dimethylorsellinic Acid Derived Meroterpenoids from Eupenicillium sp 6A-9, a Fungus Isolated from the Marine Sponge Plakortis simplex

Two rare 6(D)/5(E) ring-fused meroterpenoids, eupeniacetal A (1) and eupeniacetal B (2), and three new meroterpenoids, 1-methoxy-hydropreaustinoid A1 (3), hydroberkeleyone B (4), and 22-deoxy-10-oxominiolutelide B (5), as well as five known meroterpenoids, 22-deoxyminiolutelide B (6), preaustinoid A1 (7), berkeleyone C (8), berkeleyacetal A (9), and preaustinoid A3 (10), have been isolated, through the aid of LC-MS, from the sponge-derived fungus Eupenicillium sp. 6A-9. The structures of these meroterpenoids were elucidated by detailed spectroscopic analysis, comparison with literature data, and single-crystal X-ray diffraction. The absolute configurations were assigned by means of TDDFT/ECD and [](D) calculations as well as by X-ray diffraction analysis. These compounds showed inhibitory activity towards TNF- production in the induced THP-1 cell line but were inactive against normal tumor cell lines.