Comparison of collisionally activated dissociation mass spectra for the identification of cyclopeptides and cyclodepsipeptides

Collisionally activated dissociation (CAD) spectra of protonated molecules of cyclopeptides and cyclodepsipeptides obtained with two different mass sp ectrometry systems were compared. Fragmentations were obtained either from collisions induced in the ion source of an electrospray mass spectrometer f itted with a single quadrupole by increasing the extracting cone voltage or from collisions with an inert gas in a free-field area of a fast-atom bomb ardment (FAB) mass spectrometer. Similar Fragmentation pathways were produc ed with the two configurations even though actual tandem mass spectrometry experiments with magnetic and electric sectors provided more information th an cone-induced dissociations. However, only the latter mode allowed us to perform mass spectrometric analyses coupled to liquid chromatography (LC/ES I-MS) at low cost on commercially widespread instruments. Copyright (C) 199 9 John Wiley & Sons, Ltd.