Cytotoxic and Antibacterial Meroterpenoids Isolated from the Marine-Derived Fungus sp. M27416.

Three novel meroterpenoids, taladrimanins B-D (-), were isolated from the marine-derived fungus sp. M27416, alongside three biogenetically related compounds (-). We delineated taladrimanin B's () structure using HRESIMS and NMR, confirmed its configuration via quantum chemical NMR analysis and DP4+ methodology, and verified it through X-ray crystallography. ECD calculations determined the absolute configuration of compound , while comparative NMR and ECD analyses elucidated the absolute configurations of and . These compounds are drimane-type meroterpenoids with a C10 polyketide unit (8-configuration). We proposed a biosynthetic pathway and noted that compound showed cytotoxic activity against MKN-45 and 5637 cell lines and selective antibacterial effects against CICC 10384.