Mass-spectrometric analysis of some derivatives of α,β-didehydrotryptophan and peptides including it

It has been established that the mass spectra of N-Bz, and N-Ac derivatives of peptides containing α,β-didehydrotryptophan residues have characteristic peaks of ions with m/e 130, 156 (157), and 183; these permit the identification in peptides of the α,β-didehydrotryptophan residue, which is unstable on hydrolysis. In the course of the fragmentation of dehydropeptides by the amino acid route, the formation of the intense peak of the ion of an azlactone of aN-acyl-α,β-didehydrotryptophan is characteristic. The mass-spectrometric method can be used for determining the amino acid sequences of peptides containing α,β-didehydrotryptophan residues.