Collision-induced dissociation (CID) experiments on protonated carnosine, [carnosine + H]+, with several collision energies were shown to yield eleven different fragment ions with the generation of product ions [carnosine-H2O + H]+ and [carnosine-NH3 + H]+ being the lowest energy processes. Energy-resolved CID showed that at slightly higher collision energies the ions [histidine + H]+ and [histidine-H2O-CO + H]+ are formed. At even higher energies four other product ions were observed, however, attained relatively lower abundances. Quantum chemistry calculations, carried out at different levels of theory, were employed to probe fragmentation mechanisms that account for all the experimental data. All the adopted computational protocols give similar energetic trends, and the range of the calculated free energy barrier values for the generation of all the observed product ions is in agreement with the fragmentation mechanisms offered here.

Collision-induced dissociation products of the protonated dipeptide carnosine: Structural elucidation, fragmentation pathways and potential energy surface analysis

Ritacco I.;
2015-01-01

Abstract

Collision-induced dissociation (CID) experiments on protonated carnosine, [carnosine + H]+, with several collision energies were shown to yield eleven different fragment ions with the generation of product ions [carnosine-H2O + H]+ and [carnosine-NH3 + H]+ being the lowest energy processes. Energy-resolved CID showed that at slightly higher collision energies the ions [histidine + H]+ and [histidine-H2O-CO + H]+ are formed. At even higher energies four other product ions were observed, however, attained relatively lower abundances. Quantum chemistry calculations, carried out at different levels of theory, were employed to probe fragmentation mechanisms that account for all the experimental data. All the adopted computational protocols give similar energetic trends, and the range of the calculated free energy barrier values for the generation of all the observed product ions is in agreement with the fragmentation mechanisms offered here.
2015
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/4734292
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 5
  • ???jsp.display-item.citation.isi??? 4
social impact