Several aminoacylbenzylamines and their analogs were synthesized and analyzed by electrospray ionization mass spectrometry together with high-resolution and tandem mass spectrometric techniques. Fragment ions ([M + H - CH3NO](+)) were observed and attributed to a transfer of the benzyl group to the N-terminal amino group, leading to elimination of formamide. The proposed mechanism is supported by accurate mass measurements, and by experiments on deuterium labeling and variations of functional groups.
Copyright 2001 John Wiley & Sons, Ltd.