title: Antioxidant activity of knotwood extractives and phenolic compounds of selected tree species.
abstract: The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by gas chromatography combined with mass spectrometry. Most of the investigated wood species were rich in hydrophilic extractives (10-20% of the dry wood) with one or a few compounds dominating in each extract. All extracts had a high antioxidative potency and/or radical scavenging capacity as compared to the well-known antioxidants Trolox and butylated hydroxyanisole. The pure wood-derived lignans and taxifolin also had a high antioxidative potency and/or radical scavenging capacity. However, the antioxidant potency and/or radical scavenging capacity of several of the hydrophilic knotwood extracts were higher than that of the dominating compounds in pure form.
authors.affiliation: Process Chemistry Centre, Forest Products Chemistry, Abo Akademi University, Porthansgatan 3, FIN-20500 Turku/Abo, Finland. stefan.willfor@abo.fi
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Willför
authors.forename: Markku O
authors.initials: MO
authors.lastname: Ahotupa
authors.forename: Jarl E
authors.initials: JE
authors.lastname: Hemming
authors.forename: Markku H T
authors.initials: MH
authors.lastname: Reunanen
authors.forename: Patrik C
authors.initials: PC
authors.lastname: Eklund
authors.forename: Rainer E
authors.initials: RE
authors.lastname: Sjöholm
authors.forename: Christer S E
authors.initials: CS
authors.lastname: Eckerman
authors.forename: Suvi P
authors.initials: SP
authors.lastname: Pohjamo
authors.forename: Bjarne R
authors.initials: BR
authors.lastname: Holmbom
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D016166:Free Radical Scavengers / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D015227:Lipid Peroxidation / Q000187:drug effects; D010545:Peroxides / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D013481:Superoxides / Q000737:chemistry; D014197:Trees / Q000737:chemistry*; D014934:Wood
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010545:Peroxides; D010936:Plant Extracts; D013481:Superoxides; C049375:perhydroxyl radical