Free radical scavengers from the medicinal mushroom Inonotus xeranticus and their proposed biogenesis

New free radical scavengers, inoscavin D (1) and methylinoscavin D (2), were isolated from the methanolic extract of the fruiting bodies of Inonotus xeranticus (Hymenochaetaceae), along with the known compounds phelligridin D (3), 3,4-dihydroxybenzaldehyde (4), and 3,4-dihydroxybenzoic acid (5). Their structures were established by various spectroscopic analyses. Compounds 1 and 3 were proposed to be biosynthesized from the oxidative coupling of the precursor hispidin with 3,4-dihydroxybenzaldehyde and 3,4-dihydroxybenzoic acid, respectively. These compounds exhibited significant scavenging activity against the ABTS radical cation, and compounds 2 and 4 displayed moderate superoxide radical scavenging activity.

New free radical scavengers 1 and 2 were isolated from the methanolic extract of the fruiting body of the medicinal mushroom Inonotus xeranticus, along with the known compounds phelligridin D, 3,4-dihydroxybenzaldehyde, and 3,4-dihydroxybenzoic acid. Their structures were established by extensive spectroscopic data. Compounds 1 and 3 were proposed to be biosynthesized from the oxidative coupling of the precursor hispidin with 3,4-dihydroxybenzaldehyde and 3,4-dihydroxybenzoic acid, respectively. These compounds exhibited significant free radical scavenging activityFigure optionsDownload as PowerPoint slide