Synthesis, structure, interaction with DNA and cytotoxicity of a luminescent copper(II) complex with a hydrazone ligand

Abstract

A luminescent copper(II) complex [CuII(L)H2O]2SO4,1a was synthesized with the acyclic tridentate 2-hydroxy naphthaldehyde-2-pyridylhydrazone ligand, HL, 1. The molecular structure of 1a clearly shows that it is a monomeric copper(II) complex with CuN2OOW coordination with slightly distorted square planar geometry. The asymmetric unit of 1a contains two independent complex molecules and a sulfate anion. DNA binding interactions of 1a have been investigated by absorption, emission, viscosity and thermal denaturation studies. The cytotoxic activity of 1a was measured in vitro against the HeLa cells. The LD50 value was calculated as 4.97μM. There was no nuclear fragmentation observed after treatment with 1a, which revealed that the copper(II) complex 1a was not capable of inducing apoptosis. The cell cycle analysis of 1a indicated a dose dependent decrease of G0/G1 and S-phase cell population and dose-dependent increase of G2/M population compared with untreated control cell.