title: A selective lignin-degrading fungus, Ceriporiopsis subvermispora, produces alkylitaconates that inhibit the production of a cellulolytic active oxygen species, hydroxyl radical in the presence of iron and H(2)O(2).
abstract: A cellulolytic active oxygen species, hydroxyl radicals (.OH), play a leading role in the erosion of wood cell walls by brown-rot and non-selective white-rot fungi. In contrast, selective white-rot fungi have been considered to possess unknown systems for the suppression of .OH production due to their wood decay pattern with a minimum loss of cellulose. In the present paper, we first report that 1-nonadecene-2,3-dicarboxylic acid, an alkylitaconic acid (ceriporic acid B) produced by the selective white-rot fungus Ceriporiopsis subvermispora intensively inhibited .OH production by the Fenton reaction by direct interaction with Fe ions, while non-substituted itaconic acid promoted the Fenton reaction. Suppression of the Fenton reaction by the alkylitaconic acid was observed even in the presence of the Fe(3+) reductants, cysteine and hydroquinone. The inhibition of .OH production by the diffusible fungal metabolite accounts for the extracellular system of the fungus that attenuates the formation of .OH in the presence of iron, molecular oxygen, and free radicals produced during lignin biodegradation.
mesh_terms: D000478:Alkylation; D001487:Basidiomycota / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D006861:Hydrogen Peroxide / Q000378:metabolism*; D017665:Hydroxyl Radical / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D008031:Lignin / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism*
chemical_list: D003998:Dicarboxylic Acids; D017382:Reactive Oxygen Species; D013386:Succinates; D017665:Hydroxyl Radical; D008031:Lignin; D006861:Hydrogen Peroxide; D007501:Iron; C005229:itaconic acid