Meroterpenoid and Diphenyl Ether Derivatives from Penicillium sp. MA-37, a Fungus Isolated from Marine Mangrove Rhizospheric Soil

Penicillium sp. MA-37, which was obtained from the rhizospheric soil of the mangrove plant Bruguiera gymnorrhiza, exhibited different chemical profiles in static and shaken fermentation modes. Three new meroterpenoid derivatives, 4,25-dehydrominiolutelide B (1), 4,25-dehydro-22-deoxyminiolutelide B (2), and isominiolutelide A (3), together with three known ones were characterized from its static fermentation, while three new diphenyl ether derivatives, namely, Δ1′,3′-1′-dehydroxypenicillide (4), 7-O-acetylsecopenicillide C (5), and hydroxytenellic acid B (6), along with five related metabolites were isolated from the shaken culture. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and the structure of compound 2 was confirmed by X-ray crystallographic analysis. The absolute configurations of 1–3 and 6 were determined by ECD and modified Mosher’s method, respectively. All isolated compounds were evaluated for brine shrimp lethality and antibacterial activity.