RAPID ANALYSIS OF STEROIDAL SAPONIN MIXTURE USING ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY COMBINED WITH SEQUENTIAL TANDEM MASS-SPECTROMETRY

Using electrospray ionization mass spectrometry (MS) combined with seq uential tandem MS(ESI-MSn), two major steroidal saponins extracted fro m Tribulus terrestris were studied, and considerable useful structural information was obtained. The structure of the proposed known steroid al saponin was verified, and the structure of the unknown saponin was investigated using MSn experiments. Some special fragment ions were al so observed, and the corresponding fragmentation mechanisms were inves tigated which are characteristic for steroidal saponins and can give s ome information on the linkage position of some sugar groups in saponi ns. This methodology has been established as a powerful tool for the r apid, comparative analysis of mixtures such as crude plant extracts. ( C) 1998 John Wiley & Sons, Ltd.