Synthesis and Structural Characterization of Amino-Based Pyranoanthocyanins with Extended Electronic Delocalization

Abstract

Two new pyranoanthocyanin amino derivatives with extended electronic delocalization were obtained from the reaction of methyl­pyranomalvidin-3-O-glucoside with two amino-derived cinnamaldehydes, 4-(dimethylamino)- and 4-(diethylamino)-cinnamaldehyde. Structural characterization revealed the presence of a butadienylidene linkage connecting the pyranoanthocyanin and the cinnamyl moieties. The unexpected red color presented by the new molecules is due to the presence of a dicationic form of the pigments at acidic pH as confirmed by ESI–MS.

Key words

pyranoanthocyanin - amino derivatives - extended electronic delocalization - butadienylidene linkage - dicationic form

• References and Notes

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