Tetra-acylated cyanidin 3-sophoroside-5-glucosides from the flowers of Iberis umbellata L. (Cruciferae)

The structures of 11 acylated cyanidin 3-sophoroside-5-glucosides (pigments 1-11), isolated from the flowers of Iberis umbellata cultivars (Cruciferae), were elucidated by chemical and spectroscopic methods. Pigments 1-11 were acylated with malonic acid, p-coumaric acid, ferulic acid, sinapic acid and/or glucosylhydroxycinnamic acids. Pigments 1-11 were classified into four groups by the substitution patterns of the linear acylated residues at the 3-position of the cyanidin. In the first group, pigments 1-3 were determined to be cyanidin 3-O-[2-O-(2-O-(acyl)-beta-glucopyranosyl)-6-O-(trans-p-coumaroyl)-p-glucopyranoside]-5-O-[6-O-(malonyl)-beta-glucopyranoside], in which the acyl moiety varied with none for pigment 1, ferulic acid for pigment 2 and sinapic acid for pigment 3. In the second one, pigments 4-6 were cyaniclin 3-O-[2-O-(2-O-(acyl)-beta-glucopyranosyl)-6-O-(4-O-(beta-glucopyranosyl)-trans-p-coumaroyl)-p-glucopyranosidel-5-O-[6-O-(malonyl)-p-glucopyranosidel, in which the acyl moiety varied with none for pigment 4, ferulic acid for pigment 5 and sinapic acid for pigment 6. In the third one, pigments 7-9 were cyanidin 3-O-[2-O-(2-O-(acyl)-beta-glucopyranosyl)-6-O-(4-O-(6-O-(trans-feruloyl)-p-glucopyranosyl)-trans-p-coumaroyl)-p-glucopyranosidel-5- 0-[6-0-(j-nalonyl)-p-glucopyranosidel, in which the acyl moiety varied with none for pigment 7, ferulic acid for pigment 8, and smapic acid for pigment 9. In the last one, pigments 10 and 11 were cyanidin 3-O-[2-O-(2-O-(acyl)-beta-glucopyranosyl)-6-O-(4-O-(6-O-(4-O-(beta-glucopyranosyl)-trans-feruloyl)-beta-glucopyranosyl)-trans-p-coumaroyl)-beta-glucopyranoside]-5-O-[6-O-(malo nyl)-p-glucopyranosidel, in which acyl moieties were none for pigment 10 and ferulic acid for pigment 11. The distribution of these pigments was examined in the flowers of four cultivars oft umbellatabyHPLC analysis. Pigment 1 acylated with one molecule ofp-coumaric acid was dominantly observed in purpleviolet cultivars. On theotherhand, pignients(9 and 11)acylated with three moleCUlesot'hydroxychinamic acids were observed in lilac (purple-violet) cultivars as major anthocyanins. The bluing effect and stability on these anthocyanin colors were discussed in relation to the molecular number ofhydroxycinnamic acids in these anthocyanin molecules. (c) 2008 Elsevier Ltd. All rights reserved.