Terpenoids from the mushroom-associated fungus Montagnula donacina.

Molecular identification suggested an edible mushroom, which was previously named as Craterellus odoratus should be revised as Montagnula donacina. A chemical re-investigation of the culture broth of this fungus resulted in the isolation of four rare tetracyclic bergamotane-type sesquiterpenoids, namely donacinolides A and B, donacinoic acids A and B, and three cadinane-type ones, namely donacinols A-C and a meroterpenoid (Z)-4-hydroxy-3-(3-hydroxy-3-methylbut-1-en-1-yl)benzoic acid. Their structures were established via extensive spectroscopic methods, single crystal X-ray diffraction analysis, and computational methods. (Z)-4-Hydroxy-3-(3-hydroxy-3-methylbut-1-en-1-yl)benzoic acid showed antibacterial activity against Staphylococcus aureus.