A New Antioxidant Pyrano[4,3-c][2]benzopyran-1,6-dione Derivative from the Medicinal Mushroom Fomitiporia ellipsoidea

A new pyrano[4,3-c][2]benzopyran-1,6-dione derivative antioxidant, named phelligridin K (1), was isolated from the methanol extract of the fruiting bodies of Fomitiporia ellipsoidea, together with the known compounds, (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (2), hispidin (3), inoscavin C (4), and inonoblin B (5). Their structures were elucidated by means of extensive NMR and MS data analysis. Compounds 1, 4 and 5 exhibited significant scavenging activity against the ABTS radical cation.