Synthesis, characterization and anticancer activity of two ternary copper(ІІ) Schiff base complexes

Abstract

Two ternary copper(II) Schiff base complexes 2Cu(C14H8NO3F)(C12H8N2)·3CH3OH (1) and 2Cu(C14H8NO3Cl)(C12H8N2)·3CH3OH (2) were synthesized and characterized by IR spectroscopy, elemental analysis, and single crystal X-ray diffraction. X-ray crystallography shows that both of the copper atoms adopt square pyramidal geometry. Each copper atom is five coordinated by one nitrogen atom from –CN–, two nitrogen atoms from 1,10-phenanthroline, one hydroxyl oxygen atom and one carboxylate oxygen atom. The proteasome is often found to be overactive in cancer cells. It has also been found that cancer cells are more sensitive to proteasome inhibition than normal cells. Therefore proteasome inhibitors are pursued as antitumor drugs. The anticancer activity of the two complexes was studied. The results showed that complex (1) can significantly inhibit the cellular proliferation of human breast cancer MDA-MB-231 cells. In addition, it has proteasome-inhibitory activity in human breast cancer MDA-MB-231 cells. The inhibition of the tumor proteasomal activity resulted in the accumulation of ubiquitinated proteins and ubiquitinated form of IκB-α, (a natural proteasome substrate) followed by induction of apoptosis. The results suggest that the fluorine-containing copper complex, as a potent proteasome inhibitor, has potential to be developed into a novel anticancer drug.