Studies on the fragmentation pathways of ingenol esters isolated from Euphorbia esula using IT-MSn and Q-TOF-MS/MS methods in electrospray ionization mode

► We studied the fragmentation pathways of ingenol esters firstly. ► Seventeen standards were provided. ► Both IT-MSn and Q-TOF-MS/MS were used. ► The IT-MSn determined the elimination order of the acyloxy groups. ► The Q-TOF-MS provided high resolution mass spectra of the parent and product ions.