A new seco-pimarane diterpene and four new β-resorcylic acid lactones from a fungicolous Hypomyces subiculosus

Abstract

One new pimarane diterpene (1) and four new β-resorcylic acid lactones (2–5), together with eight known compounds (6–13) were isolated from the solid culture of the fungicolous Hypomyces subiculosus. The structures of the new compounds were elucidated using extensive spectroscopic methods, including 1D and 2D NMR, HRESIMS, CD experiments, and chemical means. Compound 1 is a ring cleavage pimarane diterpene possessing a bicyclic ring system. All compounds were evaluated for cytotoxic activities. Only compound 7 showed moderate cytotoxicity against the A549 cell line with an IC₅₀ of 44.5 μM.