Cytotoxic cardenolide glycoside from the seeds of Cerbera odollam.

A cardenolide glycoside, 3 beta-O-(2'-O-acetyl-l- thevetosyl)-15(14-->8)-abeo-5 beta-(8R)-14-oxo-card-20(22)-enolide (2'-O-acetyl cerleaside A), was isolated from a methylene chloride extract of the seeds of Cerbera odollam, together with four known compounds: cerleaside A, 17 alpha-neriifolin, 17 beta- neriifolin and cerberin. Their structures were elucidated by spectroscopic methods. All compounds except cerleaside A exhibited cytotoxic activities against oral human epidermoid carcinoma (KB), human breast cancer cell (BC) and human small cell lung cancer (NCI-H187).