Characterisation of anthocyanidins by electrospray ionisation and collision-induced dissociation tandem mass spectrometry

The present study describes the use of electrospray ionisation mass spectro metry, in combination with collision-induced dissociation (CID) and tandem mass spectrometry, for the structural characterisation of anthocyanidins an d their O-glycosides. The high-energy CID spectra of [M-Cl](+) ions of the free aglycones show characteristic fragmentation pathways, which provide us eful information about the substitution pattern in the A- and B-rings of ea ch compound. The major fragmentation observed in the high-energy CID spectr a of [M-Cl](+) ions of anthocyanins involves loss of the mono- or disacchar ide units resulting in ions containing only the aglycone moiety. From the s pectral data, the identity of the aglycone can be established as well as th e number and the class of monosaccharide units in the O-glycosides. Copyrig ht (C) 2001 John Wiley & Sons, Ltd.