New diacylated delphinidin 3-rutinoside-5-glucosides isolated from the blue-purple flowers of Browallia speciosa

Two new diacylated delphinidin 3-rutinoside-5-glucosides were isolated from the blue-purple flowers of Browallia speciosa cv. 'Purple'. As, a, major anthocyanin (1), delphinidin 3-O-[6-O-(4-O-(trans-caffeoyl)-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside]-5-O-[2-O-(trans-p-coumaroyl)-beta-D-glucopyranoside] was determined by chemical and spectroscopic methods. Another one was tentatively assigned to be the cis-p-coumroyl isomer of the major anthocyanin due to its small amount available. In the pigment 1, the 5-glucose residue of the anthocyanin is acylated with p-coumaric acid at 2-OH group of the sugar moiety, and this acylation pattern is the first report in plants.