quercetin-3-o-glucuronide and caffeic-acid

The indigo plant (Polygonum tinctorium Lour) has been used traditionally as a medicinal plant with a variety of biological effects. Of these, polyphenolic ingredients are postulated to contribute to these activities. However, the identification and quantification of polyphenolic compounds in indigo plants have not been conducted comprehensively until now. This study was undertaken to identify the related ingredients by combined instrumental analyses using ultra-performance liquid chromatography electrospray-ionisation mass spectrometry and gas chromatography-mass spectrometry after the extracts of plant tissues were fractionated by absorption column chromatography. These analyses allowed the identification of kaempferol, quercetin-3-O-glucuronide, quercetin, kaempferol-3-O-glucopyranoside, caffeic acid, chlorogenic acid and tentative 3,5,4'-trihydroxy-6,7-methylenedioxyflavone. Furthermore, predominant polyphenolic compounds were quantified by reverse-phase high-performance liquid chromatography and capillary gas chromatography, revealing the higher proportions of kaempferol, quercetin-3-O-glucuronide and quercetin among them. The results indicate that the indigo plant is a promising source for flavonoids and the related compounds with beneficial medicinal effects.

Topics: Caffeic Acids; Chlorogenic Acid; Chromatography, Gas; Chromatography, High Pressure Liquid; Kaempferols; Polygonum; Polyphenols; Quercetin; Spectrometry, Mass, Electrospray Ionization