Analysis of antioxidant flavonoids from asteraceae and moraceae plants by capillary electrophoresis

Summary Antioxidant flavonoids from the plantsSolidago gigantea Ait.,Taraxacum officinale Wiggers and Webers (Asteraceae) andMorus nigra L. (Moraceae) have been analysed by capillary electrophoresis (CE).Solidago gigantea was investigated because of its diuretic, spasmolytic, antiphlogistic, and wound-healing effect,Taraxacum officinale because it has been shown to have good diuretic and choleretic activity, andMorus nigra because it is also widely regarded as a diuretic and antidiabetic agent. Aqueous and methanolic extracts of these plants have antioxidant properties. Because their flavonoid composition might be important in their free-radical-scavenging activity, a capillary electrophoretic method was developed for characterization of the flavonoids present. We identified quercetin-3-O-β-rutinoside (rutin), quercetin-3-O-β-d-glucoside (isoquercitrin), and chlorogenic acid as the most abundant compounds inSolidago gigantea andMorus nigra, and apigenin-7-O-β-glucoside, luteolin-7-O-β-glucoside, and chlorogenic acid inTaraxacum officinale. We also discovered that quercetin-3-O-α-rhamnoside (quercitrin) and quercetin-3-O-β-galactoside (hyperoside) were absent from our sample ofSolidago gigantea and quercitrin fromMorus nigra. Quantitative analysis of these extracts was performed by high-performance liquid chromatography (HPLC). Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001