Curtisians A similar to D, new free radical scavengers from the mushroom Paxillus curtisii

In our continuous investigation for free radical scavengers from extracts o f fruit body of basidiomycetes, we have isolated four new p-terphenyl compo unds, designated as curtisians A-D, from the methanolic extract of the frui t body of Paxillus curtisii. These compounds were isolated by silica gel an d Sephadex LH-20 column chromatographies, preparative-TLC and HPLC, consecu tively. The structures of curtisians were assigned as p-terphenyls with sub stituents of acetyl, benzoyl, phenylbutyryl, 3-hydroxybutyryl and 3-acetoxy butyryl. Curtisians A, B, C and D exhibited inhibitory activity against lip id peroxidation with IC50 values of 0.15, 0.17, 0.24 and 0.14 mu g/ml, resp ectively.