Synthesis, Characterization and Bioactivity of Three Tetrazole Carboxylate Based Co(II) Complexes

As a kind of multifunctional materials with high porosity, tunable pore structure and easy functionalization, coordination complexes have been widely used in various fields. Here, three complexes were prepared by self-assembly with Co(II) ions using tetrazolylacetic acids as ligands, 2,2 ',2 ''-(benzene-1,3,5-triyltris(2H-tetrazole-5,2-diyl)) triacetic acid (H(3)tzpha), 2-(5-(pyrazin-2-yl)-2H-tetrazol-2-yl) propanoic acid (Hpztzma) and 2-(5-(pyridin-2-yl)-2H-tetrazol-2-yl) acetic acid (Hpytza), and were characterized by X-ray crystallography. These complexes can also self-assemble into nanoparticles (NPs) in aqueous solution by nanocoprecipitation. In vitro CCK-8 assay on three kind of human cancer cells (HeLa, HepG2 and Huh7) cells showed these Co(II) complexes have the best cytotoxicity against HeLa cells. And complex 1 had a half maximal inhibitory concentration (IC50 value) of 14.8 mu g mL(-1), which was superior to 16.5 mu g mL(-1) and 15.2 mu g mL(-1) of complex 2 and 3. In addition, the effect of different ligands on cancer cell ablation was explored. The results showed the three NPs can effectively inhibit the proliferation of cancer cells in vitro and provided a strategy on designing highly efficient anticancer materials based on coordination complexes.