Synthesis of oleandrin derivatives and their cytotoxic activity.

A series of oleandrin-4'-yl ester derivatives were designed, synthesized, and evaluated for their proliferation inhibition activities against tumor cell lines. Cytotoxicity data revealed that the C4' moiety had an important influence on cytotoxic activity. Several compounds that we designed and synthesized exhibit significant in vitro antiproliferative activity against the tested tumor cell lines. Among the derivatives of OL, 4b-HCl not only had good anti-tumor activity but also had good water solubility. Furthermore, 4b-HCl can significantly inhibit tumor growth by 96.4% at a dose of 6 mg/kg/d by ip.