title: Kinetic comparisons of anthocyanin reactivities towards 2,2'-azobis(2-amidinopropane) (AAPH) radicals, hydrogen peroxide and tert-buthylhydroperoxide by capillary zone electrophoresis.
abstract: Twelve major anthocyanins identified in bilberry extracts were studied in vitro using capillary zone electrophoresis (CZE) for their reactions towards 2,2'-azobis(2-amidinopropane) (AAPH) radicals, hydrogen peroxides (H(2)O(2)) and tert-buthylhydroperoxides (t-BuOOH). Reactivity towards AAPH radicals was primarily determined by the aglycon structure, not by the type of sugar moiety. Delphinidins carrying three-hydroxyl groups on the B ring were most reactive followed by cyanidins, with two-hydroxyl groups. Further, methylation of the hydroxyl groups reduced reactivity towards AAPH radicals. However, reactivity of anthocyanins towards H(2)O(2) was not significantly affected by aglycon structure or by the type of sugar moiety; there being no marked difference in reaction rates among the anthocyanins. Reactivity towards t-BuOOH was essentially the same as towards H(2)O(2), although the reaction rate was several times smaller. Also, the reaction rate of anthocyanin towards peroxide was relatively high compared to that of (+)-catechin (approximately 30 times larger) measured as a reference antioxidant, whereas the reactivities of anthocyanins and (+)-catechin towards AAPH radicals were similar.
authors.affiliation: Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichiyanagi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hatano
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsugo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Konishi
mesh_terms: D000578:Amidines / Q000737:chemistry*; D000872:Anthocyanins / Q000737:chemistry*; D019075:Electrophoresis, Capillary; D005609:Free Radicals / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D016877:Oxidants / Q000737:chemistry*; D013329:Structure-Activity Relationship; D020122:tert-Butylhydroperoxide / Q000737:chemistry*
chemical_list: D000578:Amidines; D000872:Anthocyanins; D005609:Free Radicals; D016877:Oxidants; C046728:2,2'-azobis(2-amidinopropane); D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide