Gas-phase fragmentation reactions of protonated benzofuran- and dihydrobenzofuran-type neolignans investigated by accurate-mass electrospray ionization tandem mass spectrometry

Author(s)

Dias, Herbert J. ^[1] ; Baguenard, Manon ^[2] ; Crevelin, Eduardo J. ^[1] ; Palaretti, Vinicius ^[1] ; Gates, Paul J. ^[3] ; Vessecchi, Ricardo ^[1] ; Crotti, Antonio E. M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Poitiers, Inst Chim, Poitiers - France

^[3] Univ Bristol, Sch Chem, Bristol, Avon - England

• Document type: Journal article
• Source: Journal of Mass Spectrometry; v. 54, n. 1, p. 35-46, JAN 2019.
• Web of Science Citations: 0

Abstract

We have investigated gas-phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate-mass electrospray ionization tandem and multiple-stage (MSn) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ({[}M + H-MeOH](+)), C ({[}B-MeOH](+)), D ({[}C-CO](+)), and E ({[}D-CO](+)) upon collision-induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features. In the case of compounds displaying an acetoxy group at C-4, product ion C produces diagnostic ions K ({[}C-C2H2O](+)), L ({[}K-CO](+)), and P ({[}L-CO](+)). Formation of product ions H ({[}D-H2O](+)) and M ({[}H-CO](+)) is associated with the hydroxyl group at C-3 and C-3 `, whereas product ions N ({[}D-MeOH](+)) and O ({[}N-MeOH](+)) indicate a methoxyl group at the same positions. Finally, product ions F ({[}A-C2H2O](+)), Q ({[}A-C3H6O2](+)), I ({[}A-C6H6O](+)), and J ({[}I-MeOH](+)) for DBNs and product ion G ({[}B-C2H2O](+)) for BNs diagnose a saturated bond between C-7 ` and C-8 `. We used these structure-fragmentation relationships in combination with deuterium exchange experiments, MSn data, and Computational Chemistry to elucidate the gas-phase fragmentation pathways of these compounds. These results could help to elucidate DBN and BN metabolites in in vivo and in vitro studies on the basis of electrospray ionization ESI-CID-MS/MS data only. (AU)

• FAPESP's process: 14/23604-1 - Computational chemistry: a tool to studies of mass spectrometry, reactivity and fragmentation/reaction mechanisms of organic compounds
• Grantee: Ricardo Vessecchi Lourenço
• Support Opportunities: Regular Research Grants
• 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 Opportunities: Regular Research Grants