A New Pimarane Diterpenoid from the Botryotinia fuckeliana Fungus Isolated from Deep‐Sea Water

A new pimarane diterpenoid, named botryopimarene A (1), was discovered from the fungus Botryotinia fuckeliana MCCC 3 A00494 isolated from the deep‐sea water, together with ten known compounds. The planar structure of 1 was established based on the extensive spectroscopic analyses. The absolute configurations of tricyclic system in 1 were resolved by the theoretical ECD calculation, while the 15,16‐diol moiety in the side chain was resolved by the Mo2(OAc)4‐induced ECD spectrum. Compound 1, featuring a Δ9(11) double bond, was rarely discovered in pimarane family. Compounds 1–11 were tested for their cytotoxic activities using six human cancer cell lines by the MTT method. However, none of the compounds exhibited detectable cytotoxicities (IC50 >20 μm).