Antioxidant p-terphenyl compound, isolated from edible mushroom, Boletopsis leucomelas

A new acetyl p-terphenyl derivative, boletopsin 15, was isolated from the ethyl acetate extract of fruit bodies of the Basidiomycete Boletopsis leucomelas, together with 4 known compounds. The structures of these compounds were elucidated by spectral analysis as well as by directly comparing the spectral data of the new compound with those of known compounds. The free radical-scavenging activity of the compounds was assayed using the 2,2-diphenyl-1-picrylhydrazyl scavenging method. The results showed that compounds 1 and 2 exhibited significant antioxidant activity (1: EC50 = 2.1 µm and 2: EC50 = 6.6 µm).