Antioxidant Properties of Oak Bracket Mushroom, Pseudoinonotus dryadeus (Higher Basidiomycetes): A Mycochemical Study.

A complex mixture of free fatty acids (1), cerevisterol (2), a sphingosine (3), and a complex mixture of diacylglycerophospholipids (4) were isolated from the fruiting body of the basidiomycete mushroom Pseudoinonotus dryadeus and subjected to spectroscopic analyses. The antioxidant activities of the whole extract of the fungus, of the isolated fractions, and of compounds 1-4 were evaluated in two in vitro model systems: 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and superoxide anion. In each systems, the extract of fungus and compound 2 showed the same free radical scavenging activity (with SC50 data of 18.27 µg/mL and 5.75 µg/mL, respectively) compared with the positive control quercetin (DPPH assay). Compounds 1-4 were isolated from P. dryadeus for the first time.

Lipid Metabolites from the Mushroom Meripilus giganteus.

The phytochemical investigation of the methanolic extract of the white rot fungus Meripilus giganteus resulted in the isolation and identification of complex mixtures of free fatty acids (1), monoacylglycerols (2), cerebrosides (3), ergosterol (4) and ergosterol peroxide (5). The structures of the isolated lipid metabolites (1-5) were determined by chemical and spectroscopic methods. The antioxidant activity of the whole MeOH extract of the fungus was evaluated through in vitro model systems, such as 2,2-diphenyl-l-picrylhydrazyl (DPPH) and superoxide anion. In all two systems, the results indicated that the extract of the fungus showed the same free-radical-scavenging activity with SC50 data of 47.70 µg/mL, compared with the positive control quercetin (DPPH assay). None of the isolated compounds (1-5) showed a significant activity. Compounds 2-4 were isolated from Meripilus giganteus for the first time.