ACYLATED CYANIDIN GLYCOSIDES IN THE VIOLET-BLUE FLOWERS OF IPOMOEA-PURPUREA

Six acylated cyanidin glycosides were isolated from violet-blue flower s of Ipomoea purpurea. These anthocyanins were all based on cyanidin 3 -sophoroside-5-glucoside, acylated with caffeic acid and/or p-coumaric acid. Three anthocyanin structures were elucidated to be cyanidin ta- D-glucopyranosyl)caffeyl)-beta-D-glucopyranosyl a-D-glucopyranoside]-5 -O-[beta-D-glucopyranoside], cyanidin -D-glucopyranosyl)caffeyl)-beta- D-glucopyranosyl)- ta-D-glucopyranoside]-5-O-[beta-D-glucopyranoside] and cyanidin -[2-O-(6-O-(trans-caffeyl)-beta-D-glucopyranosyl)- a-D-gl ucopyranoside]-5-O-[beta-D-glucopyranoside]. These three anthocyanins were present in all 12 violet-blue flower strains as major pigments. T he colours of these acylated anthocyanins were stabler in neutral solu tion than their deacyl analogues.