Singlet oxygen quenching by anthocyanin's flavylium cations

Abstract

The quenching of singlet molecular oxygen ((1)O(2)) by the flavylium cation form of six widespread anthocyanin derivatives: cyanidin 3-glucoside (CG), cyanidin 3-rutinoside (CR), cyanidin 3-galactoside (CGL), malvidin (M), malvidin 3-glucoside (MG) and malvidin 3,5-diglucoside (MDG) was studied in 1% HCl methanol solution by time-resolved phosphorescence detection (TRPD) of (1)O(2) and photostationary actinometry using perinaphthenone and methylene blue as sensitizers, respectively. The average value of the total (k(0)) and chemical (k(c)) quenching rate constants were approximately 4 x 10(8) M(-1) s(-1) and 3 x 10(6) M(-1) s(-1), respectively, indicating the good performance of the studied anthocyanins as catalytic quenchers of (1)O(2). The quenching efficiency was larger for malvidin than for cyanidin derivatives, probably by the extra electron-donating methoxy group in ring B of the malvidin derivatives; and it was also dependent on the number and type of glycosylated substitution. As observed for other phenolic-like derivatives, the quenching of (1)O(2) by anthocyanins was mediated by a charge-transfer mechanism, which was modulated by the total number of -OR substituents that increases the electron-donating ability of these compounds.

Quantitative studies on structure–ORAC relationships of anthocyanins from eggplant and radish using 3D-QSAR

“…3a and b. The conclusion is consistent with the study by Rosso et al (De Rosso, Moran Vieyra, Mercadante, & Borsarelli, 2008), indicating that the antioxidant activity of anthocyanins is probably due to the steric hindrance effects of bulky glycoside groups. Additionally, the presence of additional electron-donating and/or hydrophobic groups around the glycosylation might enhance the radical scavenging activity (Figs.…”

Inhibition of Low-Density Lipoprotein Oxidation by Nagano Purple Grape (Vitis vinifera×Vitis labrusca)

“…We also confirmed the antioxidant activity of resveratrol and L-ascorbic acid using the lag time assay (data not shown). These results confirm data that has been reported previously (28,(39)(40)(41)(42). Taken together, the results suggest in addition to resveratrol and L-ascorbic acid, anthocyanins including Cy-3-glu and its metabolite may also suppress LDL oxidation in humans.…”

Chemical Analysis of Extracts from Newfoundland Berries and Potential Neuroprotective Effects

“…We tested levels of cyanidin-3-galactoside in extract samples from V. vitis-idaea . We successfully detected a level of 66.33 mg/100 g cyanidin-3-galactoside in Newfoundland V. vitis-idaea , which is noteworthy since this compound is considered to have fairly high antioxidant activity [33]. …”

“…Antioxidant compounds obtained in the diet or through dietary supplementation could be beneficial for combating reactive oxygen and nitrogen species, which can contribute to the development of several disorders, including cancer, cardiovascular disease, diabetes and neurodegeneration [33,36,37]. Our laboratory has a specific interest in identifying natural compounds that may be neuroprotective.…”