Six Diacylated Anthocyanins from the Storage Roots of Purple Sweet Potato, Ipomoea batatas

Eight acylated anthocyanins were isolated from the storage roots of the purple sweet potato, Ipomoea batatas cv Yamagawamurasaki, which is the source of the food colorant "purple sweet potato color." Of these, six pigments were identified as diacylated anthocyanins, cyanidin and peonidin 3-O-(6-O-(E)-caffeyl-2-O-(6-O-acyl- β-D-glucopyranosyl)-β-D-glucopyranoside)-5-O-β-D-gluco-pyranosides, in which each acyl subsutituent was a p-hydroxybenzoyl, (E)-caffeyl or (E)-ferulyl residue, mainly by NMR analyses.