A study of characteristic fragmentation of different C- and O-glycosylation position flavonoids and their aglycone by quadrupole time-of-flight tandem mass spectrometry

Flavonoids are important bioactive natural compounds, so the differentiation and structural characterization of flavonoids are important research topics. This research results provided valuable mass spectral data and reliable information for the identification of different C- and O-glycosylation position flavonoids and their aglycone. The high resolution electrospray ionization quadrupole time-of-flight tandem mass spectrometry was employed to identify one 8-C-glycosyl flavonoid, one 4'-O-glycosyl, one 7-O-glycosyl, and two 3-O-glycosyl flavonoids and four aglycone in negative and positive ion mode with collision-induced dissociation. The characteristic ions of different C- and O-glycosylation position flavonoids and their aglycone were summarized and the fragmentation pathways were proposed in negative and positive ion mode. The MS/MS spectra obtained by UHPLC/Q-TOF-MS/MS analysis could be used for the structural characterization and differentiation of these compounds. These results have practical applications for the rapid identification and structural characterization of these compounds present in crude bioactive extracts or mixtures.