Diterpenoids profile of E. paralias and E. geniculata using UPLC-ESI/MS spectrometry

Euphorbia species contain series of macrocyclic diterpenoids which present as mono, di and sometimes triesters and were reported to possess several and diverse biological activities. The aim herein was to use the ultra-performance coupled to the positive ion mode electron spray ionization mass spectroscopy (UPLC-ESI-MS) as an analytical tool for rapid screening and tentative identification of diterpenoids in the methylene chloride fractions of Euphorbia paralias and Euphorbia geniculata. The identification of compounds was based on ESI-MS and ESI-MS/MS fragmentation pattern, in addition to comparison with reported literature. Five classes were determined including tigliane, ingenane, lathyrane, daphnane and jatrophane diterpenoids esters. Each class of the detected diterpenoids obtained its characteristic ESI-MS/MS fragmentation which facilitates its identification. As a result, a total of fifty-two diterpenoids were identified and characterized in Euphorbia paralias and Euphorbia geniculata. All of these compounds are first report in the two plants by this method. Peak 35 was tentatively identified as ingenol-20-hydroxyheptanoate which expected to be a new compound. The results demonstrated that the used method could be a rapid, and an effective analytical tool for screening and characterization of diterpenoids in the complex systems of plant extracts.