Fragmentation of a series of cyclic dipeptides in fast-atom bombardment mass spectrometry.

The positive-ion mass spectra of a series of cyclic dipeptides have been obtained by fast-atom bombardment mass spectrometry. The protonated molecules were mass selected and their collision-induced dissociations were analysed by tandem mass spectrometry. This approach allowed an easy structural characterization of the above mentioned class of compounds for further pharmacological studies.