Synthesis and antitumor activity of des-AB analogue of steroidal saponin OSW-1

Simplified des-AB-type aglycone of antitumor steroidal saponin OSW-1 was concisely prepared starting from readily available Hajos ketone. We further completed the synthesis of des-AB-OSW-1 analogue by the installation of the disaccharide moiety into the des-AB aglycone, and evaluated its antitumor activity. The results indicated that a truncated aglycone drug design strategy based on OSW-1 would be a promising approach for the development of novel antitumor agents.