engleski

DPPH radical inhibition kinetic and antiradical activity of polyphenols from chokeberry and elderberry fruits

Chokeberry and elderberry fruits are a rich source of polyphenols, the compounds with significant antiradical and chelating properties. They are studied intensively because of beneficial effects on the human health. In this study, three fractions enriched with different polyphenol classes were isolated from chokeberry and elderberry to study their antiradical activity using the DPPH test. The first fraction contained flavonols and phenolic acids, the second anthocyanins, and the third proanthocyanidins. The polyphenol content was determined by reversed- phase high performance liquid chromatography. Anthocyanins were found to be the main polyphenolic components of these berries with the highest portion in the total antiradical activity, followed by proanthocyanidins and phenolic acids and flavonols. Furthermore, proanthocyanidins were found to be more effective in free DPPH• radical scavenging than flavonols, phenolic acids and anthocyanins. A biphasic reaction was observed in the reaction between DPPH• radicals and polyphenols, with “ fast” and “ slow” scavenging rates. All polyphenol classes showed strong antiradical activity in first fast period, while in slow period antiradical activity of polyphenols decreased. This kind of biphasic reaction could be important in the biological activity of chokeberry and elderberry. This study is a contribution to a better understanding of antiradical activity of polyphenols from chokeberry and elderberry.

chokeberry ; elderberry ; antiradical activity ; anthocyanins ; proanthocyanidins ; flavonols ; phenolic acids

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