title: Chemical studies of proanthocyanidins and hydrolyzable tannins.
abstract: We investigated a number of natural polyphenols representing flavan-3-ols, gallotannins, and ellagitannins with regard to their antioxidant potential. For this purpose we used pulse radiolysis to determine scavenging rate constants with hydroxyl radicals and decay rates of the respective aroxyl radicals and EPR spectroscopy to identify the radicals after in situ oxidation. Using NMR spectroscopy, we could confirm phenolic coupling reactions of epigallocatechin gallate and pentagalloyl glucose after radical-induced oxidation.
authors.affiliation: Institut für Strahlenbiologie, GSF Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Germany. bors@gsf.de
authors.forename: W
authors.initials: W
authors.lastname: Bors
authors.forename: L Y
authors.initials: LY
authors.lastname: Foo
authors.forename: N
authors.initials: N
authors.lastname: Hertkorn
authors.forename: C
authors.initials: C
authors.lastname: Michel
authors.forename: K
authors.initials: K
authors.lastname: Stettmaier
mesh_terms: D000872:Anthocyanins / Q000737:chemistry* / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy; D006861:Hydrogen Peroxide / Q000737:chemistry; D006868:Hydrolysis; D047348:Hydrolyzable Tannins / Q000031:analogs & derivatives* / Q000737:chemistry; D017665:Hydroxyl Radical; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D010100:Oxygen / Q000378:metabolism; D019800:Phenol / Q000378:metabolism; D044945:Proanthocyanidins; D013634:Tannins / Q000737:chemistry* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D047348:Hydrolyzable Tannins; D044945:Proanthocyanidins; D013634:Tannins; C013515:ellagitannin; C013221:proanthocyanidin; D017665:Hydroxyl Radical; D019800:Phenol; C435084:pentagalloylglucose; D002392:Catechin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate; D010100:Oxygen