Application of electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry techniques for the profiling of steroidal saponin mixture extracted from Tribulus terrestris

Using electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry (ESI-MSn), the steroidal saponin mixture extracted from Tribulus terrestris was studied. The structures of five known steroidal saponins and two unknown steroidal saponins in the saponin mixture were investigated by sequential tandem mass spectrometry experiments. All of the steroidal saponins displayed similar fragmentation behavior in ESI-MSn, and the characteristic cross ring cleavage pattern could be used as a fingerprint for the identification of steroidal saponins. The methodology has been established as a powerful tool for the profiling of mixtures, especially of crude plant extracts, and the structural elucidation of compounds.