Psathyrellins A-E, Antibacterial Guanacastane Diterpenoids from Mushroom Psathyrella candolleana.

Five previously undescribed guanacastane diterpenoids, namely psathyrellins A-E (1-5), were obtained from cultures of the mushroom Psathyrella candolleana. Their structures with absolute configurations were elucidated by extensive spectroscopic methods. Compounds 1-3 showed antibacterial activity against four strains with MIC values in a range of 16-128 μg/mL.