Fig. 3 Oleanolic Acid and CDDO
UA derivatives have been synthesized after oxidation, lactoseization and ring-opening reaction with increased cytotoxicity to NTUB1 cells compared to UA by 2-fold 51 (Fig.4A ), providing new insights for the further development of its derivatives. Moreover, UA derivatives containing N-acyl imidazole or N-alkyl imidazole derivatives with the help of α,β-unsaturated ketone have also been characterized as significant anticancer activity 52(Fig.4B ). Introduction of N-alkyl heterocyclic motifs bound to α,β-unsaturated ketones in ring A can provide better Michael receptors, which allows UA derivatives to interact with certain target proteins interaction potentially.