Flavonoids From the Flowers and Leaves of the Himalayan Megacodon stylophorus (Gentianaceae)

Five flavonol O-glycosides and 4 C-glycosylflavones were isolated from the flowers of the Himalayan Megacodon stylophorus (Gentianaceae). They were characterized as quercetin 3- O-glucoside (1), quercetin 3- O-rutinoside (2), kaempferol 3- O-glucoside (3), isorhamnetin 3- O-glucoside (4) and kaempferol 3,7-di- O-glucoside (5) (flavonols), and isovitexin (6), isoorientin (7), isovitexin X″- O-arabinoside (8) and isovitexin 4′- O-glucoside (9) ( C-glycosylflavones) by ultraviolet, liquid chromatography-mass spectrometry, acid hydrolysis, nuclear magnetic resonance, and/or high-performance liquid chromatography and thin-layer chromatography comparisons with authentic samples. On the other hand, 5 C-glycosylflavones were isolated from the leaves and identified as 6, 7, 9, vitexin (10), and orientin (11). Although many C-glycosylflavones and xanthones have been reported from Gentianaceae species, flavonols are minor occurrence in the family. Flavonoids were reported from the Megacodon species for the first time.