Structural Elucidation of Eighteen Cerebrosides from Holothuria Coronopertusa in a Complex Mixture by High-Energy Collision-Induced Dissociation of [M + Li]+ Ions

Eighteen cerebrosides were detected in admixture from the sea cucumber Holothuria coronopertusa. Their structures have been established on the basis of liquid-secondary ion mass spectrometry (LSIMS)experiments. The collision-induced dissociation (CID)of the lithiated molecules ([M + Li]+)led to diagnostic fragment ions which were further identified by tandem mass spectrometry (MS/MS). In the present study, the combination of LSIMS as ionization mode and high-energy MS/MS analysis appears to be a very powerful method for the rapid analysis of unresolved mixtures of complex molecules.