Abstract
Novel Pd(II) and Cu(II) complexes have been synthesized by the reaction of Na-2 PdCl4 and CuCl2 center dot 2H(2)O with fluorinated enaminone ligand leading to the formation of complexes having the formulae [Pd(enm)Cl-2] and [Cu-2(diCO)(4)]; where enm and diCO are enaminone and deprotonated dicarbonyl containing ligands, respectively. The structures and geometry of the two metal chelates have been elucidated by applying alternative spectral and analytical tools including elemental analysis, FT-IR spectra, H-1 NMR spectra and UV-Vis spectra. The molecular structure of the Cu(II) complex has been determined by single crystal X-ray diffraction; the complex crystalizes in monoclinic P21/c space group. Square pyramidal geometry has been confirmed for Cu(II) complex where Pd(II) complex has the expected square planar geometry. The mechanism of the in-situ conversion of the enaminone to dicarbonyl ligand with CuCl2 center dot 2H(2)O was illustrated. The type of interaction between the two complexes and salmon sperm DNA (SS-DNA) has been studied applying absorption spectra and viscosity measurements. The binding constant values (kb) was calculated to be (1.17 +/- 0.6) x 10(4) and (3.62 +/- 0.4) x 10(4) M-1 for Pd(enm)Cl-2 and Cu-2(diCO)(4), respectively, which confirmed the interaction of the two complexes with DNA via intercalative mode of interaction. Intercalative binding mode between the studied compounds and DNA was further confirmed by the results of viscosity measurements. The anticancer activity of the two metal complexes has been evaluated against breast cancer cell line (MCF-7) and the liver cancer cell line (HepG-2) in comparison with the well-known anticancer drug cis-DDP. Surprisingly, we found that Cu-2(diCO)(4) complex has activity (IC50 = 3.26 mu g/mL) against a human liver cancer cell line (HepG2) exceeding the efficiency of the reference drug cis-DDP (IC50 = 3.67 mu g/mL).