Two new strophanthidol cardenolides from the seeds of Antiaris toxicaria

► Toxicarioside N and toxicarioside O were new compounds. ► The new cardenolides belong to strophanthidol cardenolide, which usually shows strong cytotoxic activities and is rare reported. ► The four compounds were found to possess strong cytotoxic activity with minimum IC50 values of 0.011 μM.