Co-pigmentation effect of quercetin glycosides on absorption characteristics of cyanidin glycosides and color of Red Wing azalea

Abstract

A quercetin 5-methyl ether and five quercetin glycosides were isolated from flowers of Red Wing azalea 1 but were found only in trace amounts in an orange sport of this cultivar. The anthocyanins (cyanidin glycosides) extracted from the orange and red flowers were identical, even though the absorption spectra of the intact cells differed. The absorption spectrum of the orange sport was simulated with a 10 −3 M aqueous solution of cyanidin 3,5-diglucoside at the pH of the tissue, 2·8. The absorption spectrum of Red Wing was matched with cyanidin 3,5-diglucoside at the same concentration and pH, co-pigmented with the 3-rhamnoside or galactoside of quercetin.