FRAGMENTATION REACTIONS OF CU-CATIONATED ALPHA-AMINO-ACIDS()

The Cu+-cationated species of 12 alpha-amino acids have been prepared by fast-atom bombardment and the unimolecular (metastable ion) fragmen tation reactions have been examined by tandem mass spectrometry. The m ajor unimolecular fragmentation reactions observed involve elimination of H2O, elimination of CO2 and elimination of CH2O2. In addition, for Cu+-cationated asparagine and glutamine, elimination of NH3 is a sign ificant reaction and for Cu+-cationated proline, elimination of H-2 is a major fragmentation reaction. It is concluded that there are three pathways to elimination of (H-2, C, O-2), direct elimination of CH2O2, direct elimination of (H2O + CO) and elimination of (CO2 + H-2).