Antiradical and reductant activities of anthocyanidins and anthocyanins, structure-activity relationship and synthesis

卷:194

Ali, Hussein M. ; Almagribi, Wafaa ; Al-Rashidi, Mona N.

Ain Shams Univ

关键词: Anthocyanins;    Antioxidants;    SAR;    Radical stabilization;    Semiquinone resonance;   

DOI  :  10.1016/j.foodchem.2015.09.003

学科分类：食品科学和技术

【 摘 要 】

Eight anthocyanidins, seven anthocyanins and two synthesized 4'-hydroxy flavyliums were examined as hydrogen donors to DPPH, ABTS and hydroxyl radicals, and as electron donors in the FRAP assay. Most compounds gave better activities than trolox and catechol. A structure-activity relationship (SAR) study showed that, in the absence of the 3-OH group, radicals of the 4, 5 or 7-OH groups can only be stabilized by resonance through pyrylium oxygen, while 3-OH group improved hydrogen atom donation because of the stabilization by anthocyanidin semiquinone-like resonance. Electron donation was also enhanced by the 3-OH group. Both anthocyanidins and their respective anthocyanins showed similar trends and close activities. Different types of sugar unit bonded to the 3-OH group or counter ion had minor effect on activities. The catechol structure improved both hydrogen and electron donation. Compounds lacking the catechol structure had a decreasing order of H-atom and electron donation (Mv > Pn > Pg > Ap > 4'-OH-flavylium) consistent with the decreasing number of their hydroxyl and/or methoxy groups. (C) 2015 Elsevier Ltd. All rights reserved.