Synthesis, characterization and in vitro anti-proliferative effects of pentacyclic triterpenoids

A series of glycyrrhetinic acid, oleanolic acid and ursolic acid derivatives were designed and synthesized. Structures of all novel compounds were determined by 1H NMR, 13C NMR, and HRMS methods. In vitro anti-proliferative effects of all compounds were evaluated against A549, Hela and HepG2 cancer cell lines. The three compounds G2, G3 and G4 showed better anti-proliferative effects than the positive control doxorubicin on the three kinds of cancer cells. The two compounds O1 and U11 showed better anti-proliferative effects than doxorubicin on Hela cells. The four compounds O2, O3, O8 and U8 showed better anti-proliferative effects than doxorubicin on HepG2 cells. Notably, compound G3 demonstrated the strongest growth inhibitory effects with IC50 values of 0.16 ± 0.23 µM and 0.33 ± 0.41 µM on Hela and HepG2 cells, respectively, and compound G2 demonstrated the strongest growth inhibitory effect with IC50 values of 0.80 ± 1.03 µM on A549 cells.