Characteristic Peptoid Fragmentations under CID and IRMPD Conditions in Relation to the Conformations of Charged Peptoids

摘要

1. The protonated peptoids fragmented by producing predominantly Y-type ions in both the CID and the IRMPD experiments. The bias towards Y-ions was largely due to the greater proton affinity of the amino group at the terminal side of the Y-ions 2. The protonated peptoids preferred to form higher mass fragment ions under the CID experiments. In the IRMPD spectra, the intensities shifted to the medium and lower mass ions. 3. The alkali metalated peptoids fragmented by producing both the Y'- and the B'-ions, suggesting a "mobile metal cation' mechanism. 4. The alkali metalated peptoids preferred to form the medium mass ions in both the CID and the IRMPD experimetns. 5. The IRMPD experiments produced more fragment ions than the CID experiments. Some of the fragment ions have not been identified, yet.