A new proline-containing flavonol glycoside from Caragana leucophloea Pojark

Abstract

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
• flavonoids
• kaempferol-3-O-methyl-7-O-β-d-glucopyranosyl-8-(1-methyleneproline)-4′-O-β-d-glucopyranoside
• biological activities

Funding

This work was co-financed by the Hi-Tech R&D Program of China [grant number 2011AA10A202], the National Basic Research Program of China [grant number 2010CB126105] and the Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang, China [grant number BRZD1102].