title: Tocotrienamines and tocopheramines: reactions with radicals and metal ions.
abstract: The antioxidant activity of vitamin E (VE) homologs α, γ and δ-tocotrienamines (4b-6b), never studied before, and α, γ and δ-tocopheramines (4a-7a) was investigated by means of different total antioxidant capacity (TAC) tests. In all the test model systems, compounds 4a-7a and 4b-6b showed similar or higher TAC values than the parental vitamin E forms and their physiological metabolites. α-Homologs of VE amines showed markedly higher activity than the VE congeners in the TEAC test, which is tailored for liposoluble antioxidants, while γ-homologs of the amine analogs showed higher activity in the FRAP tests. Kinetics analysis of the reaction with DPPH(·) showed higher second order rate k for 4a than for α-tocopherol (1a). α-Tocopherolquinone 1f was the common main oxidation product for both 1a and α-tocopheramine (4a) exposed to ferric ions or DPPH(·), and the implied oxidative deamination of 4a was accompanied by a nitration reaction of phenolic substrates that were added to the reaction medium. Possible mechanisms of these reactions were studied.
authors.affiliation: Department of Internal Medicine, Laboratory of Clinical and Nutritional Biochemistry, University of Perugia, Perugia 06126, Italy. f.galli@unipg.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Galli
authors.forename: Francesco
authors.initials: F
authors.lastname: Mazzini
authors.forename: Luca
authors.initials: L
authors.lastname: Bamonti
authors.forename: Lars
authors.initials: L
authors.lastname: Gille
authors.forename: Stefan
authors.initials: S
authors.lastname: Böhmdorfer
authors.forename: Marta
authors.initials: M
authors.lastname: Piroddi
authors.forename: Thomas
authors.initials: T
authors.lastname: Netscher
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Kelly
authors.forename: Thomas
authors.initials: T
authors.lastname: Rosenau
mesh_terms: D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000737:chemistry; D002839:Chromans / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000138:chemical synthesis / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000588:Amines; D001713:Biphenyl Compounds; D002839:Chromans; D005290:Ferric Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D014810:Vitamin E; C004931:1,1-diphenyl-2-picrylhydrazyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid