Characterization of glucocerebrosides and the active metabolite 4,8-sphingadienine from Arisaema amurense and Pinellia ternata by NMR and CD spectroscopy and ESI-MS/CID-MS.

Sphingolipid metabolites regulate cellular processes such as cell proliferation, differentiation, and apoptosis. In this study, glucocerebrosides (GluCer) from rhizomes of Arisaema amurense and Pinellia ternata were fully characterized using 1- and 2-dimensional nuclear magnetic spin resonance (NMR) and circular dichroism (CD) spectroscopy and tandem collision-induced dissociation mass spectrometry (ESI-MS/CID-MS). Three new acylated and seven known GluCer were elucidated with 4,8-sphingadienine (4,8-SD, d18:2) as backbone. 4,8-SD is a metabolite after enzymatical hydrolysis of GluCer in the gut lumen. In this study, 4,8-SD was hydrolyzed from GluCer and chromatographically purified on silica gel. In contrast to the GluCer, 4,8-SD showed cytotoxic effects in the WST-1 assay. GluCer with 4,8-SD as sphingoid backbone are present in plants consumed as food, such as spinach, soy, and eggplant.