New features of intramolecular copigmentation by acylated anthocyanins

Abstract

Three series of structurally related anthocyanins\ extracted from the red purple ~owers of Dendrobium {Pramot|\ xLaeliocattleya cv[ Mini Purple\ Bletilla striata and Phalaenopsis all belonging to the Orchidaceae family and another series extracted from the pink ~owers of Senecio cruentus "Compositae# allowed the con_rmation of the existence of strong intramolecular copigmentation e}ects[ These interactions confer stability to the coloured forms of the molecules\ in a wide range of slightly acidic to neutral aqueous media[ Moreover\ the existence of structural relationships among the four series stressed the di}erent in~uences exerted by the diverse substituent groups[ The existence of a malonylglucoside attached to position 2 of all but three of the molecules put forward a new role for the malonyl residue\ in this particular position[