Synthesis, Characterization and Anticancer Activities of New Cu(II) Complexes

Abstract

Popular treatments of cancer such as Cisplatin have many drawbacks, including the development of chemoresistance in cancer cells and serious side effects such as nephrotoxicity and neurotoxicity. Therefore, there is a need for development of more efficient, target‐specific, and less toxic cancer drugs. Copper complexes have shown to be a promising alternative, partly because copper, an essential element for most aerobic organisms, is involved in many biological pathways as structural and catalytic cofactor. Additionally, studies have shown a correlation between serum copper level and different aspects of cancers. We have synthesized and evaluated the biological activities of Cu‐quinoline thiazole (CuQ(oBt)) and Cu‐pyridine thiazole (Cu(Py(oBt))2). The nuclease activities of these complexes were visualized via gel electrophoresis. We found that Cu(Py(oBt))2 and CuQ(oBt), in the presence of a reductant, convert supercoil (SC) DNA to the single‐nicked (SN) and double‐nicked (DN) forms with high but different efficiencies. The binding of complexes to DNA was further investigated using electronic absorption and fluorescence spectroscopy. Fluorescence spectroscopy with bovin serum albumin (BSA) showed that the complexes can bind to serum proteins. The comparison of results provides insights for aspects of the ligand frames that affect the DNA‐binding, protein‐binding, and nuclease activities for copper complexes.