Structural characterization of cyanidin-3,5-diglucoside and pelargonidin-3,5-diglucoside anthocyanins: Multi-dimensional fragmentation pathways using high performance liquid chromatography-electrospray ionization-ion trap-time of flight mass spectrometry

Abstract

Cyanidin-3,5-diglucoside and pelargonidin-3,5-diglucoside were identified from an extract of freeze-dried red hybrid-tea rose petals with high mass accuracy and multi-dimensional fragmentation using liquid chromatography-electrospray ionization-ion trap-time of flight mass spectrometry (LC-ESI-IT-TOF-MS). The effects of varying the amount of collision energy applied to the trap at each MS stage were studied to optimize subsequent fragmentation steps. Structural characterization of cyanidin and pelargonidin was attempted by identifying the fragments created by cross-ring cleavage (CRC) of the C-ring and small neutral molecule loss. These fragments were further determined to be diagnostic for differentiating the compounds of interest. A computational study of the CRC fragments of cyanidin was performed in order to calculate the overall energy of the fragments. It was determined that the 0,2 CRC pathway was more favorable than the 0,3 CRC pathway.