Characterization of the anthocyanins of Catharanthus roseus (L.) G. Don in vivo and in vitro by electrospray ionization ion trap mass spectrometry

The power of direct infusion electrospray (ESI) mass spectrometry and ion trap multiple mass spectrometry (MS/MS) were applied to the detection and identification of the anthocyanic compounds of Catharanthus roseus (L.) G. Don. Cell suspensions of C. roseus, fresh flowers from both in vitro regenerated and field-grown plants, were comparatively examined. The anthocyanic extracts were analyzed by positive-ion electrospray ionization mass spectrometry and collision experiments were performed on molecular ions by means of ion trap facilities. In parallel, classical approaches such as thin layer chromatography (TLC) and UV/Vis spectroscopy were undertaken. Petunidin, malvidin and hirsutidin, already known in the literature, were identified as aglycones. Three 3-O-glucoside derivatives, supposed to be present on the basis of literature data, were also identified. Moreover, three 3-O-(6-O-p-coumaroyl)glucosides were identified for the first time in this species. Using the direct ESI-MS/MS approach, the mass spectra of all the anthocyanic compounds present in the extracts can be obtained, even of those occurring in traces and not detectable by TLC. The three extracts investigated showed the same qualitative anthocyanic profile, but large quantitative differences