Synthesis of novel oleanolic acid and ursolic acid in C-28 position derivatives as potential anticancer agents

A series of nitrogen-containing derivatives of oleanolic acid and ursolic acid were prepared by a modification at C-28 position via esterification with 2-hydroxyacetic acid followed by amidation with amines, such as piperazine, N-methylpiperazine, and alkane-1, 2-diamines, alkane-1, 4-diamines, alkane-1, 6-diamines. In vitro antiproliferative activities of the compounds prepared towards MCF-7, Hela and A549 cell lines were evaluated by a MTT method to show that OA-5a, OA-5b, OA-5c and UA-5a showed somewhat improved antiproliferative activities against MCF-7, Hela and A549 cells comparing to that of the positive control, gefitinib.