title: Elucidating collision induced dissociation products and reaction mechanisms of protonated uracil by coupling chemical dynamics simulations with tandem mass spectrometry experiments.
abstract: In this study we have coupled mixed quantum-classical (quantum mechanics/molecular mechanics) direct chemical dynamics simulations with electrospray ionization/tandem mass spectrometry experiments in order to achieve a deeper understanding of the fragmentation mechanisms occurring during the collision induced dissociation of gaseous protonated uracil. Using this approach, we were able to successfully characterize the fragmentation pathways corresponding to ammonia loss (m/z 96), water loss (m/z 95) and cyanic or isocyanic acid loss (m/z 70). Furthermore, we also performed experiments with isotopic labeling completing the fragmentation picture. Remarkably, fragmentation mechanisms obtained from chemical dynamics simulations are consistent with those deduced from isotopic labeling.
authors.affiliation: Université d'Evry Val d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Boulevard François Mitterrand, 91025, Evry, France.|CNRS-UMR 8587, Evry, France.
authors.forename: Estefanía Rossich
authors.initials: ER
authors.lastname: Molina
authors.affiliation: Institut Rayonnement Matière de Saclay, NIMBE/CEA, LIONS, Bât. 546, F-91191, Gif-sur-Yvette Cedex, France.|CNRS-UMR 3685, Gif-sur-Yvette Cedex, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ortiz
authors.affiliation: Université d'Evry Val d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Boulevard François Mitterrand, 91025, Evry, France.|CNRS-UMR 8587, Evry, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Salpin
authors.affiliation: Université d'Evry Val d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Boulevard François Mitterrand, 91025, Evry, France.|CNRS-UMR 8587, Evry, France.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Spezia
mesh_terms: D056004:Molecular Dynamics Simulation; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014498:Uracil / Q000737:chemistry*
chemical_list: D011522:Protons; D014498:Uracil
keywords: chemical dynamics simulations; collision induced dissociation; gas-phase reaction mechanisms; nucleobase fragmentation; retro Diels Alder