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Chemical structure of fomitellan A, a polysaccharide with a mitogenic effect isolated from the fruiting bodies of Fomitella fraxinea, has been assigned as a mannofucogalactan with a repeating unit of penta-saccharide, which was composed of a (1→6)-linked d -galactopyranosyl backbone having a C-2 position substituted with disaccharide units of 3-O- d -mannopyranosyl- l -fucopyranosyl residue. The 1H and 13C NMR signals of fomitellan A have been completely assigned by extensive NMR experiments.

During the search for natural substances with PPAR-γ agonistic effect, unique polychlorinated compounds named chlorophellins A–C have been isolated together with the known compound, drosophilin A, from the methanolic extract of the fruiting body of the fungus Phellinus ribis . Their structures were assigned on the basis of NMR and mass spectrometric analyses. Chlorophellin C of compounds tested exhibited the most potent PPAR-γ agonistic effect and was comparable to rosiglitazone, a well-known PPAR-γ agonist that has been used for the therapy of type 2 diabetes.

New triterpene glucosides, oligoporins A (1), B (2), and C (3), were isolated from the methanolic extract of the fruiting bodies of Oligoporus tephroleucus (Polyporaceae). Their structures were established by spectroscopic methods. These compounds significantly exhibited protective effect to plasmid DNA damage by hydroxyl radical (*OH) generated from the Fenton reaction with hydrogen peroxide and ferrous.

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.

Three new free radical scavengers were isolated from the methanolic extract of the fruiting bodies of Inonotus xeranticus (Hymenochaetaceae), along with the known compound davallialactone. Their structures were established as hispidin analogs by extensive NMR spectral data. Compounds 3 and 4 displayed significant scavenging activity against the superoxide radical anion, ABTS radical cation, and DPPH radical, while 1 and 2 exhibited potent antioxidative activity only against ABTS radical cation.