Identification of sulfated steroidal glycosides from the starfish Heliaster helianthus by electrospray ionization mass spectrometry

The starfish Heliaster helianthus contains Thornasteroside A (1) and Helianthoside (2) and its isomer (3) as the major sulfated steroidal glycosides. Saponin containing fractions obtained by purification of extracts of H. helianthus induced escape reactions and mortality in the limpets Siphonaria lessoni and Fissurella radiosa. ESI-MS and ESI-MS/MS were successfully applied to the rapid screening of two cytotoxic fractions obtained by purification of the ethanolic extracts of arms and central disks dissected from H. helianthus. Three major compounds were identified, together with minor sulfated steroidal mono- and diglycosides of polyhydroxysteroids.