Flavonol Glycosides from the Whitish Flowers of Primula alpicola and P. sikkimensis var. hopeana in Bhutan

摘要

Five flavonols were isolated from the whitish flowers of Primula alpicola and P. sikki-mensis var. hopeana which belong to the section Sikkimensis in Bhutan. Flavonoid composition of two Primula species were qualitatively the same and they were identified as quercetin 3-O-xylosyl-(1→2)-[rhamnosyl-(1→6)-glucoside] (1), quercetin 3-O-rutinoside (2), quercetin 3-O-glucoside (3), kaempferol 3-O-rutinoside (4) and isorhamnetin 3-O-rutinoside (5). Compound 1 which might characterize in these species was reported from the family Primulaceae for the first time. Although gossypetin has been reported as principle yellow pigment in Primula species, it was not found in the whitish flowers of two Primula taxa.