The composition of radical-scavenging compounds from Geranium macrorrhizum leaves was analyzed and the antioxidative activities of various extracts was determined. Seven compounds, namely gallic acid, ellagic acid, 4-galloyl quinic acid, the flavonoid quercetin and three of its glycosides, quercetin-3-beta-glucopyranoside, quercetin-3-beta-galactopyranoside and quercetin-4'-beta-glucopyranoside were isolated and identified in the various fractions. The radical-scavenging activity of the isolated compounds was measured using DPPHcircle and ABTS(circle+) scavenging assays and compared with the activity of rosmarinic acid. Quercetin-3-glucopyranoside and quercetin-3-galactopyranoside showed the highest antioxidative capacities. Antioxidative activities of all plant fractions were assessed by model system tests (superoxide anion and hydrogen peroxide scavenging) and by oxidation tests (beta-carotene bleaching, peroxide value, UV absorbance and headspace-gas chromatography hexanal determination). The ethanol-butanol fraction of the plant possessed the highest activity in most of the tests.
- radical scavenging activity
- rapeseed oil