Qualitative on-line profiling of ceramides and cerebrosides by high performance liquid chromatography coupled with electrospray ionization ion trap tandem mass spectrometry: the case of Dracontium loretense

Ceramides and cerebrosides are key compounds in the metabolism of sphingolipids. Produced in response to a variety of apoptotic stimuli, these metabolites mediate either mitogenic or apoptotic responses, depending on cell type and nature of stimulus. Novel strategies using these selective targets for a therapeutic intervention, e.g. in cancer, cardiovascular and neurodegenerative diseases, and HIV, have been developed, along with anticancer approaches using controlled delivery of exogenous natural ceramides from ceramide-based liposomes. Thus, great is the need to find selective and sensitive analytical methods allowing a prompt detection of ceramides and cerebrosides in natural matrices. Here we report an analytical study carried out on the Amazonian plant Dracontium loretense, resulted in a preliminary analysis a rich source of this class of natural compounds. A handy, selective, and sensitive methodology based on high-performance liquid chromatography coupled to electrospray negative ionization multistage ion trap mass spectrometry (HPLC-ESI/ITMS(n)) was developed. Analysis of fingerprint multistage mass spectra allowed the rapid identification of 3 major long-chain bases and their exact pairing with 11 different fatty acids and with carbohydrate headgroups. Thus, the structures of 21 ceramide and cerebroside species, among which 7 molecules never reported before, were unambiguously assigned. Results obtained in this study demonstrated that this analytical approach could provide a reliable and sensitive method to obtain the qualitative on-line profiling of ceramides and cerebrosides in new medicinal plant matrices.