One new proline-containing flavonol glycoside, namely kaempferol-3-O-methyl-7-O-β-D-glucopyranosyl-8-(1-methyleneproline)-4'-O-β-D-glucopyranoside (1), together with 15 known flavonoids, 3-O-methylkaempferol (2), 3-O-methylquercetin (3), quercetin (4), kaempferol (5), apigenin (6), rhamnazin (7), astragalin (8), alquds (9), quercitrin (10), rutin (11), isoquercitrin (12), apigetrin (13), myricitrin (14), hesperidin (15) and calycosin-7-O-β-D-glucopyranoside (16) were isolated from the aerial parts of Caragana leucophloea Pojark. (Leguminosae). Their structures were determined on the basis of spectroscopic analyses and by comparison with literature data. Compounds 2-4 revealed a strong antimicrobial activity with minimum inhibitory concentration values of 12.5-150 μg/mL and median inhibitory concentration (IC50) values of 7.42-76.61 μg/mL. Compounds 3, 4, 6-8, 10-12 and 14 showed strong antioxidant activity. Compounds 2-7 exhibited moderate antinematodal activity on Caenorhabditis elegans with IC50 values of 40.51-68.05 μg/mL.
Keywords: Caragana leucophloea Pojark; Leguminosae; biological activities; flavonoids; kaempferol-3-O-methyl-7-O-β-d-glucopyranosyl-8-(1-methyleneproline)-4′-O-β-d-glucopyranoside.