Synthesis and anti-tumor activity of oleanolic acid derivatives

Thirteen novel oleanolic acid (OA) derivatives were designed and synthesized with modification at positions of C-3, C-12 and C-28 of OA. Their structures were confirmed by MS, ¹H NMR and elemental analysis. Their in vitro cytotoxicities against various cancer cell lines (SGC7901, MCF-7 and A549) were evaluated by MTT assay. The results indicated that the tested derivatives were found to have stronger cell growth inhibitory activity than OA. Among them, compounds II₂ and II₃ showed more potent cytotoxicity on MCF-7 and A549 tumor cells than gefitinib (positive control). They are worthy to be studied further.