Three New Cytotoxic Steroidal Glycosides Isolated from Conus pulicarius Collected in Kosrae, Micronesia

Abstract

Three new sulfated steroidal glycosides, along with known cholesterol derivatives, were isolated from the visceral extract of the cone snail Conus pulicarius. The structure of each new compound was elucidated by nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. The characteristic structural features of the new compounds include the sulfate group at the C-3 position and the xylose linked to C-7, which is different from those of known steroidal glycosides. The three new compounds were named as Conusaponin A-C, as these are the first example of steroidal glycosides isolated from Conus species. These compounds exhibited significant in vitro cytotoxicity (GI50 values down to 0.5 μM) against the K562 human leukemia cell line. This finding, combined with those regarding the previously reported steroidal glycosides with potent activities against various cancer cell lines, would provide new insights into the structure-activity relationships of cytotoxic sulfated steroidal glycosides.pectroscopy and high-resolution mass spectrometry. The characteristic structural features of the new compounds include the sulfate group at the C-3 position and the xylose linked to C-7, which is different from those of known steroidal glycosides. The three new compounds were named as Conusaponin A-C, as these are the first example of steroidal glycosides isolated from Conus species. These compounds exhibited significant in vitro cytotoxicity (GI50 values down to 0.5 μM) against the K562 human leukemia cell line. This finding, combined with those regarding the previously reported steroidal glycosides with potent activities against various cancer cell lines, would provide new insights into the structure-activity relationships of cytotoxic sulfated steroidal glycosides.