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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Gas-phase fragmentation reactions of protonated cocaine: New details to an old story

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Dias, Herbert J. [1, 2] ; Bento, Mariana V. B. [2] ; da Silva, Eder H. ; Saturnino-Junior, Andrade [2] ; de Oliveira, Marcelo F. [1] ; Vessecchi, Ricardo [1] ; Parreira, Renato L. T. [2] ; Crotti, Antonio E. M. [1]
Total Authors: 8
[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ribeirao Preto, SP - Brazil
[2] Univ Franca, Nucleo Pesquisas Ciencias Exatas & Tecnol, Franca, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Journal of Mass Spectrometry; v. 53, n. 3, p. 203-213, MAR 2018.
Web of Science Citations: 3

We have used a combination of multiple stage mass spectrometry (MSn) experiments, hydrogen/deuterium exchange experiments, and thermochemical data estimated by computational chemistry calculations at the B3LYP/6-31+G(d,p) level of theory to revisit the gas-phase fragmentation of protonated cocaine. The lone pair of nitrogen participates in major fragmentation routes of protonated cocaine, to generate cyclic iminium ions. The structure of product ion m/z 182, which has been previously proposed in the literature, was shown to be unstable; therefore, we have decided to revisit it. Here, we propose another ion structures for the product ion m/z 182 that is supported by thermochemical data. Compared with the formation of other product ions, the formation of the most intense product ions in the collision-induced dissociation spectrum of protonated cocaine (m/z 182 and m/z 82) is the most energetically favorable. We propose the structure and formation of m/z 122 and m/z 91 for the first time. We suggest that m/z 91 originates from m/z 122 instead of m/z 119, as fully supported by MSn experiments. The results of this study could help to study and quantify cocaine metabolites. (AU)

FAPESP's process: 13/20094-0 - Evaluation of the anti-parasitary and insecticidal activities of benzofuran derivatives, and study of their gas-phase fragmentation reactions using tandem mass spectrometry
Grantee:Antônio Eduardo Miller Crotti
Support type: Regular Research Grants