Cyathusals A, B, and C, antioxidants from the fermented mushroom Cyathus stercoreus

Abstract

Three new polyketide-type antioxidative compounds, cyathusals A (1), B (2), and C (3), and the known pulvinatal (4) were obtained from the fermented mushroom Cyathus stercoreus. The structures of the compounds were characterized on the basis of NMR and mass spectroscopic data. Cyathusals A, B, and C and pulvinatal showed free radical scavenging activities on the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical with EC50 values of 41.6, 46.0, 26.6, and 28.6 μM, respectively, and on the 2,2′-azinobis(3- ethylbenzothiazoline-6-sulfonate) (ABTS) cation radical with EC50 values of 7.9, 11.1, 9.1, and 8.4 μM, respectively.