Abstract
Ten flavonoids were isolated for the first time from the aerial parts of Sisymbrium irio L. grown in Saudia Arabia, using chromatographic methods, and identified as apigenin, apigenin-7-galactoside, apigenin-7-O-β-d-glucoside, luteolin-7-O-glucoside, apigenin-7-di-glucoside 5, apigenin-7-O-(6″acetyl) glucoside, apigenin-7-O-gluco(6″-1″′) rhamnoside, apigenin-7-O-gluco(6″-1″′)rhamnoside-5-methoxide, kampferol and kampferol-3-xyloside-7-galactoside. The median lethal dose of the extract was determined in mice and found to be greater than 5000mg/kg body weight, suggesting that this plant is non-toxic. Antioxidant activities were assessed for all extracts and fractions (total, ether, chloroform, ethyl acetate and butanol) and isolated compounds, and showed variable antioxidant activity, with apigenin-7-O-galactoside being the most potent.