Malvidin 3-(6-acetylglucoside)-5-glucoside and other anthocyanins from flowers of Geranium sylvaticum

Abstract From the flowers of Geranium sylvaticum five anthocyanin glycosides have been isolated by successive application of an ion-exchange resin, droplet counter-current chromatography and gel filtration. Even though the lability of the novel major (85%) anthocyanin, malvidin 3-O-(6-O- acetyl -β- d -glucopyranoside )-5-O-β- d -glucopyranoside , was high, it was possible by means of NMR spectroscopy, especially homo- and heteronuclear two-dimensional techniques, to assign all the proton and carbon atoms to give the full structure. The minor anthocyanins were identified as the 3,5-diglucosides of malvidin and cyanidin, and the 3-glucosides of cyanidin and delphinidin.