Determination of active components in Cynanchum chinense R. Br. by capillary electrophoresis.

A method for the determination of 7-O-alpha-l-rhamnopyranosyl-kaempferol-3-O-beta-d-glucopyranoside (GL) and 7-O-alpha-l-rhamnopyranosyl-kaempferol-3-O-alpha-l-rhamnopyranoside (RH) in the traditional Chinese herb Cynanchum chinense R. Br. by capillary electrophoresis has been developed. With botate buffer (30 mmol/L, pH 9.50) as running buffer and an applied voltage of 20 kV, the compounds were completely separated within 6 min and detected at UV 254 nm. The correlation coefficients of the calibration curves for GL and RH were 0.9990 and 0.9992, respectively, over the concentration ranges (15.0-1000.0 and 12.0-1000.0 microg/mL), and the recoveries were from 91.4 to 107.1%.