DETERMINATION OF NAPHTHODIANTHRONES IN PLANT-EXTRACTS FROM HYPERICUM-PERFORATUM L BY LIQUID-CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRY

The determination of the naphthodianthrone constituents in extracts of dried blossoms of Hypericum perforatum L. by combined HPLC-electrospr ay mass spectrometry is described. Hypericin (1), pseudohypericin (2) and their precursor compounds produce intensive negative quasi-molecul ar ions by deprotonation provided a non-acidic eluent system is used i n the HPLC separation. From the [M-H](-) ions formed in the electrospr ay ionization process characteristic daughter ion spectra can be obtai ned by collisional activation which have been studied by tandem mass s pectrometry. (C) 1997 Elsevier Science B.V.