Synthesis of three new copper(II) compounds for chemodynamic therapy against cancer cells

Abstract Cu(II) compounds hold great promise for chemodynamic therapy (CDT) against cancer cells because they are able to catalyze the hydrogen peroxide to form cytotoxic hydroxyl radicals by fenton-like reaction. In this paper, three Cu(II) compounds based on substituted pyridyl-thienyl-1,2,4-triazole [Cu(L1)2(ClO4)2]∙2MeCN (1) [Cu(L1)2(MeOH)2](ClO4)2 (2) and [Cu(L3)2(NO3)2]∙3H2O (3) [L1 = (3-(2-pyridyl)-4-(p-chlorophenyl)-5-(2-thienyl)-1,2,4-triazole, L2 =3-(2-pyridyl)-4-phenyl-5-(2-thienyl)-1,2,4-triazole and L3 = 3-(2-pyridyl)-4- (p-methoxyphenyl)-5-(2-thienyl)-1,2,4-triazole) were designed and synthesized by a simple method. These compounds with mononuclear structure show considerable cytotoxicity towards human cervical cancer cells (HeLa). The MTT assay suggests that compound 2 with lowest half maximum inhibitory concentration (IC50) is the most cytotoxic, compared with compounds 1 and 3. In addition, the cytotoxicity was also confirmed by the live/dead con-stained experiment. Finally, the flow cytometry demonstrates that these compounds are capable of inducing cell apoptosis by the hydroxyl radicals.