An Acylated Cyanidin 3,7-diglucoside in the Bluish Flowers of Bletilla striata ‘Murasaki Shikibu’ (Orchidaceae)

Abstract

A novel acylated anthocyanin was identified from the violet flowers of Bletilla striata ‘Murasaki Shikibu’ as a major floral anthocyanin. This pigment was based on cyanidin 3,7-diglucoside as its deacylanthocyanin, and was acylated with two molecules of caffeic acid. The structure was unambiguously elucidated by chemical and spectroscopic methods to be cyanidin 3-O-(β-glucopyranoside)-7-O-[6-O-(4-O-(6-O-(4-O-(β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranosyl)-trans-caffeoyl)-β-glucopyranoside]. Based on the results of the present study, the bluing effect was discussed for the violet flowers of a given cultivar.