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Updated: Sep 25, 2026

Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Fragmentation of dipyridamole and related dipyrimidines by electrospray ionization collisional activated
Edson Rodrigues Filho1, Adaila Marta Paixão Almeida, Marcel Tabak
1Departamento de Química, UFSCar, Universidade Federal de São Carlos, C.P. 676, C.E.P. 13565-905, São Carlos, SP, Brazil. edson@dq.ufscar.br
Abstract:
The coronary vasodilator, co-activator of antitumor compounds and antioxidant drug dipyridamole and several of its derivatives were studied by electrospray ionization (ESI) combined with collisional activated decomposition (CAD) in both positive and negative modes. These compounds produce abundant monocharged ions ([M + H](+)) under ESI. Interpretation of the CAD spectra showed that fragmentation occurs preferentially in the ethanolamine groups attached at C-2, C-4, C-6 and C-8. 2-Methoxyethanol is eliminated when ethanolamines are in positions C-2/C-6 and 2-aziridinethanol is eliminated from C-4/C-8 ethanolamines. The proposed fragmentation schemes were supported by deuterium labeling experiments and tandem mass spectrometry.
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