Trichocladinols I-K, oxatricyclic and oxabicyclic polyketides from Trichocladium opacum.

Three new polyketides, trichocladinols I-K (1-3) with oxabicyclic (1 and 3) and oxatricyclic (2) skeletons, together with three knovwnl metabolites, massarilactone G (4), massarigenin D (5), and rosigenin (6), were isolated from the solid-substrate fermentation cultures of the ascomycete fungus Trichocladium opacum. The structures of the new compounds were elucidated primarily by analysis of NMR data. The absolute configurations of 1-3 were deduced from circular dichroism (CD) data. Compounds 1-3 were tested for cytotoxicity against five human carcinoma cell lines, HeLa, A549, MCF-7, HCT116, and T24. Compound I showed a weak cytotoxic effect against HeLa cells, but 2 and 3 were inactive.