Design, synthesis, anticancer activity and mechanism studies of novel 2-amino-4-aryl-pyrimidine derivatives of ursolic acid.

A series of novel 2-amino-4-aryl-pyrimidine derivatives of ursolic acid were designed, synthesized, and evaluated for their anticancer activities against four cancer cell lines (MCF-7, HeLa, HepG2, and A549) and a human hepatocyte cell line (LO2) via MTT assay. Among these derivatives, compound 7b exhibited potent cytotoxic activity against MCF-7 and HeLa cells with IC50 values of 0.48 ± 0.11 and 0.74 ± 0.13 μM, respectively, and substantially lower cytotoxicity to LO2 cells. Further cellular mechanism studies in MCF-7 cells elucidated that compound 7b could inhibit cell migration, induce cell cycle arrest at S phase and trigger mitochondrial-related apoptosis by increasing the generation of intracellular ROS and decreasing the mitochondrial membrane potential (MMP), which was associated with upregulation of the protein expression level of Bax and downregulation the level of Bcl-2 and the activation of caspase cascade. Western blot analyses also revealed that compound 7b could simultaneously suppress RAS/Raf/MEK/ERK and PI3K/AKT/mTOR signaling pathways, which could be responsible for the induction of apoptosis. Molecular docking study revealed that MEK1 kinase could be one of the possible targets of the title compounds. These results offered a promising scaffold for the investigation of novel targeted anticancer agents. [ABSTRACT FROM AUTHOR]