Mixed ligand aroylhydrazone and N-donor heterocyclic Lewis base Cu(II) complexes as potential antiproliferative agents

Abstract

A series of four mixed ligand aroylhydrazone and N-donor heterocyclic Lewis base Cu(II) complexes [CuL(X)]₂ [L refers to the dianionic form of (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide; X=pyrazine (Pz; 1), pyridine (Py; 2), imidazole (Imz; 3) and 3-pyridinecarbonitrile (3-PyCN; 4)] has been synthesized and characterized by elemental analysis, various spectroscopic techniques and X-ray crystallography (for 1, 2 and 4). The antiproliferative effect of complexes 1-4 was examined in 4 human tumor cell lines (ovarian carcinoma (A2780), colorectal carcinoma (HCT116), lung adenocarcinoma (A549) and breast adenocarcinoma (MCF7)) and in normal human primary Fibroblasts. Complex 4 exhibits a high cytotoxic activity against ovarian and colorectal carcinoma cells (A2780, HCT116 respectively), with IC₅₀ much lower than those for normal primary fibroblasts. Complex 4 could induce cell death via apoptosis but not autophagy in colorectal carcinoma cells.

Keywords: Antiproliferative agent; Aroylhydrazone ligand; Human tumor cell lines; Mixed ligand copper(II) complexes; X-ray structure.