Phenolic antioxidants in wood smoke

Ten prominent dimethoxyphenols were determined in birchwood smoke from choked and open laboratory burning and in chimney smoke from a tiled stove. The structures of the methoxyphenols are similar to those of the well-known tocopherol and ubiquinol antioxidants. The 2.6-dimethoxyphenols characterising hardwood smoke are stronger antioxidants than the corresponding 2-methoxyphenols present mainly in softwood smoke. The antioxidant activity is highest for the 2,6-dimethoxyphenols with 4-alkenyl and 4-alkyl groups, which constitute 60-70%, of the total amount of dimethoxyphenols. Phenolic antioxidants are scavengers of oxygen radicals and should be considered when health hazards of small-scale incomplete biomass burning are estimated. (C) 2001 Elsevier Science B.V. All rights reserved.