[Study on fragmentation of vitexin and isorhamnetin-3-O-beta-D-rutinoside using electrospray quadrupole time of flight mass spectrometry].

Objective: To investigate the fragmentation pathway of vitexin and isorhamnetin-3-O-beta-D-rutinoside with CID-TOF-MS.

Method: Equipped with an LC-MS was carried out using an ultra-performance liquid chromatography, electrospray ionization quadrupole collision-induced dissociation-TOF-MS.

Result: ESI-MS spectrum showed [M-H]- base peak of m/z 431. 0958 and m/z 623.1566. The CID-MS of vitexin showed five basic fragment ions, three of which corresponded to the glucosyl ring fracture: m/z 353, 341 and 311; other two were benzyl ion m/z 283, aglycone ion m/z 269. In addition, two low abundance ions, namely, m/z 161 and m/z 117, generated by RDA cracking ions, were also characteristic ions. The CID-MS of isorhamnetin-3-O-beta-D-rutinoside showed six main characteristic fragments ions corresponding to the loss of rhamnosyl m/z 477 and the glycosyl ring fracture: m/z 387, 357 and 311, and aglycone ion m/z 315. In addition, B ring generated m/z 300 and m/z 271 and C ring generated m/z 243 and the RDA cleavage generated m/z 151 and m/z 125.

Conclusion: Those fragment ions can be used to quickly identify vitexin and isorhamnetin-3-O-beta-D-rutinoside.