Synthesis and antitumor activity evaluation of oleanolic acid saponins bearing an acetylated l-arabinose moiety.

A series of oleanolic acid derivatives bearing acetyl-substituted l-arabinose moiety has been synthesized and screened in vitro for cytotoxicity against ten cancer cell lines and four normal cell lines. The antiproliferative evaluation indicated that synthetic derivatives showed excellent selectivity, as they were toxic against only A431 cell line. Among them, the compound 6 possesses the best inhibitory activity. A series of pharmacology experiments showed that compound 6 significantly induced A431 cells apoptosis and cell cycle arrest, which could serve as a promising lead candidate for further study.