COLLISION-INDUCED DISSOCIATION IN ESI-MS/MS OF CARAMBOXIN ISOLATED FROM Averrhoa carambola: COMPUTATIONAL AND MASS SPECTROMETRY STUDIES

Star fruit belongs to the Oxalidaceae family, originally from Asia and widely distributed worldwide as a food source. Traditional knowledge advises patients with kidney problems to avoid consuming this fruit. Bioguided studies have led to the isolation of a toxin with a structural core analogous to the amino acids phenylalanine and tyrosine. Mass spectrometry (MS) is the primary technique used for analyzing biological samples, as understanding the gas-phase decomposition reactions of target analytes enhances the efficiency of these analyses. In this study, we detail the mechanisms involved in the formation of the main ion fragments of caramboxin in electrospray ionization tandem mass spectrometry (ESI-MS/MS), supported by computational chemistry and mass spectral simulations.