Structure of anthocyanin from the blue petals of Phacelia campanularia and its blue flower color development

The dicaffeoyl anthocyanin, phacelianin, was isolated from the blue petals of Phacelia campanularia and its structure was determined. Phacelianin may take both an inter- and intramolecular stacking form and shows the blue petal color by molecular association and the co-existence of a small amount of metal ions.