Collision-induced dissociation of flavonoid 7-O-diglycoside cations: elucidation of important structural motifs by selection of the cationizing reaction.

Flavonoids are ubiquitous molecules in nature and are found in almost all plants, including fruits and vegetables. Although flavonoids are structurally similar, subtle differences in their structures lead to important changes in their biological activities. Over years, mass spectrometry has become an ideal tool for the characterization of those important molecules. In particular to overcome the challenge of structure assignment, tandem mass spectrometry was used in numerous studies. In the present study, we submitted selected flavonoid 7- O-diglycosides to electrospray ionization to prepare different kinds of flavonoid ions, i.e. protonated, sodium- cationized and copper-cationized molecules. Most of the investigated reactions are already described in the literature in several papers and the aim of the present study is to present concise and coherent relations between CID reactions, cationizing agents and flavonoid 7-O-diglycoside structures. Some insights in the reaction mechanisms and the role of the cationizing particles will also be attempted.