Three new cyathane diterpenoids named stercorins A-C (1-3), including one with unusual 4,9-seco-carbon skeleton, together with two new drimane sesquiterpenoids named stercorins D (4) and E (5) were isolated from the liquid cultures of the basidiomycete Cyathus stercoreus. Their structures were established by 1D and 2D NMR data in conjunction with HR-ESI-MS. All three cyathane diterpenoids showed neurotrophic activity in PC-12 cells at concentrations of 10 µM. Compounds 1-3 significantly suppressed LPS-induced NO production in culture medium in BV2 cells with the IC50 values of 1.64 μM, 9.25 μM and 8.71 μM, respectively. Notably, Compound 1, possessing an uncommon medium-sized 9/7 ring system showed the most promising role in the prevention of two activities-associated neurodegenerative diseases.
Keywords: Cyathane diterpenoid; drimane sesquiterpenoid; neurodegenerative diseases; neurotrophic activity.