A RAPID SCREENING METHOD FOR ARTEMISININ AND ITS CONGENERS USING MS MS - SEARCH FOR NEW ANALOGS IN ARTEMISIA-ANNUA

A rapid screening method based on tandem mass spectrometry (ms/ms) is described for artemisinin-related compounds present in complex matrice s. These compounds produce abundant ammonium adducts, [M+NH4)+, using ammonia desorption chemical ionization (dci), and dissociation of the mass-selected adducts yields the protonated molecules, [M+H]+, which s ubsequently eliminate characteristic neutral molecules (H2O, CO, HCO2H , HOAc). Neutral loss ms/ms scans which are selective for different el imination reactions were used in order to screen for groups of related analogues present in a crude hexane extract of Artemisia annua. Compa rison of ms/ms product spectra of known Artemisia compounds with those of the new analogues provided information on the functional groups an d the molecular weights of the new compounds present in rhe plant, and tentative structures are suggested.