Kaempferol Glycosides in the Flowers of Carnation and their Contribution to the Creamy White Flower Color

Abstract

Three flavonol glycosides were isolated from the flowers of carnation cultivars ‘White Wink’ and ‘Honey Moon’. They were identified from their UV, MS, ¹H and ¹³C NMR spectra as kaempferol 3-O-neohesperidoside, kaempferol 3-O-sophoroside and kaempferol 3-O-glucosyl-(1→2)-[rhamnosyl-(1→6)-glucoside]. Referring to previous reports, flavonols occurring in carnation flowers are characterized as kaempferol 3-O-glucosides with additional sugars binding at the 2 and/or 6-positions of the glucose. The kaempferol glycoside contents of a nearly pure white flower and some creamy white flower lines were compared. Although the major glycoside was different in each line, the total kaempferol contents of the creamy white lines were from 5.9 to 20.9 times higher than the pure white line. Thus, in carnations, kaempferol glycosides surely contribute to the creamy tone of white flowers.