Identification of Barrenwort flavonoids by high-resolution tandem mass spectrometry

Fragmentation of the main Barrenwort flavonoids—icariin, icaritin, icarisides I and II, and epimedins A and B—is studied by tandem mass spectrometry. High-resolution mass spectra of positively charged ions of these compounds are obtained under the conditions of collision-induced dissociation. Characteristic fragment ions are determined, which ensured the classification of unknown compounds as Barrenwort flavonoids. Epimedin C was isolated from raw plant material by preparative liquid chromatography; its structure was confirmed by ¹H and ¹³C NMR spectra.