Acylated cyanidin glycosides from the pale- violet flowers of Ionopsidium acaule (Desf.) Rchb. (Brassicaceae)

摘要

Three new acylated cyanidin 3-sambubioside-5-glucosides (1-3) and one new acylated cyanidin 3-(3(X)-glucosylsambubioside)-5-glucoside (4) were isolated from the pale-violet flowers of Ionopsidium acaule (Desf.) Rch beta, together with one known anthocyanin. These new pigments were determined by chemical and spectroscopic methods to be cyanidin 3-O-[2-O-(beta-xylopyranosyl)-6-O-(4-O-(6-O-(trans-feruloyl)-beta- glucopyranosyl)-trans-p-coumaroyl)-b-glucopyranoside]-5-O-[6-O-(malonyl) -b-glucopyranoside] (1), cyanidin 3-O-[2-O-(2-O-(trans-feruloyl)-beta-xylopyranosyl)-6-O-(4-O-(beta-glucop yranosyl)-trans-pcoumaroyl)-beta-glucopyranoside]-5-O-[6-O-(malonyl)-b-g lucopyranoside] (2), cyanidin 3-O-[2-O-(2-O( trans-feruloyl)-beta-xylopyranosyl)-6-O-(4-O-(6-O-(trans-feruloyl)-beta- glucopyranosyl)-trans-p-coumaroyl)- b-glucopyranoside]-5-O-[6-O-(malonyl)-beta-glucopyranoside] (3) and cyanidin 3-O-[2-O-(2-O-(trans-feruloyl)-3-O-(beta-glucopyranosyl)-beta-xylopyrano syl)-6-O-(4-O-(6-O-(trans-feruloyl)-b-glucopyranosyl)- trans-p-coumaroyl)-beta-glucopyranoside]-5-O-[6-O-(malonyl)-beta-glucopy ranoside] (4). These polyacylated cyanidin glycosides are responsible for the pale-violet flower color of I. acaule, and the contribution of the number of hydroxycinnamic acid residues to the bluing effect was discussed.