Gas‐phase fragmentation of γ‐lactone derivatives by electrospray ionization tandem mass spectrometry |
| |
Authors: | Antonio E M Crotti Erika S Bronze‐Uhle Paulo G B D Nascimento Paulo M Donate Sérgio E Galembeck Ricardo Vessecchi Norberto P Lopes |
| |
Affiliation: | 1. Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeir?o Preto—USP, Ribeir?o Preto, SP, Brazil;2. Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, Brazil;3. Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeir?o Preto—USP, Ribeir?o Preto, SP, Brazil;4. Departamento de Farmacologia, Faculdade de Medicina de Ribeir?o Preto—USP, Ribeir?o Preto, SP, Brazil |
| |
Abstract: | Fragmentation reactions of β‐hydroxymethyl‐, β‐acetoxymethyl‐ and β‐benzyloxymethyl‐butenolides and the corresponding γ‐butyrolactones were investigated by electrospray ionization tandem mass spectrometry (ESI‐MS/MS) using collision‐induced dissociation (CID). This study revealed that loss of H2O M + H ?18]+ is the main fragmentation process for β‐hydroxymethylbutenolide (1) and β‐hydroxymethyl‐γ‐butyrolactone (2). Loss of ketene (M + H ?42]+) is the major fragmentation process for protonated β‐acetoxymethyl‐γ‐butyrolactone (4), but not for β‐acetoxymethylbutenolide (3). The benzyl cation (m/z 91) is the major ion in the ESI‐MS/MS spectra of β‐benzyloxymethylbutenolide (5) and β‐benzyloxymethyl‐γ‐butyrolactone (6). The different side chain at the β‐position and the double bond presence afforded some product ions that can be important for the structural identification of each compound. The energetic aspects involved in the protonation and gas‐phase fragmentation processes were interpreted on the basis of thermochemical data obtained by computational quantum chemistry. Copyright © 2009 John Wiley & Sons, Ltd. |
| |
Keywords: | carbonyl compounds collision‐induced dissociation theoretical calculations gas‐phase ion chemistry γ ‐butyrolactone |
|
|