The dasyscyphins A-C and niveulone, new biologically active compounds from the ascomycete Dasyscyphus niveus.

In the course of a screening for cytotoxic compounds from fungi four new terpenoid metabolites, named dasyscyphins A, B, C, and niveulone were isolated from fermentations of Dasyscyphus niveus strain A0101. While dasyscyphin A (1) exhibited no significant biological activities in our test systems dasyscyphin B (2) and dasyscyphin C (3) showed cytotoxic activities against human (HepG2, Hela S3, U937, Colo-320, Jurkat) cell lines with IC50-values of 0.5-3 microg/ml while the activity of niveulone (4) was less pronounced. Only modest or weak antibiotic properties were observed for (2) and (3).