Cadmium(ii) complexes with a 4-acyl pyrazolone derivative and co-ligands: crystal structures and antitumor activity?

RSC Advances Pub Date: 2016-12-01 DOI: 10.1039/C6RA23938B

Abstract

Three cadmium(II) complexes, [Cd(HL)2(CH3OH)2]·(CH3OH) (1), [Cd(HL)2(bpy)]·(CH3OH)2 (2), and [Cd(HL)2(phen)]·(CH3OH)1.5 (3), (where H2L = N-(1-phenyl-3-methyl-4-(4-chlorobenzoyl)-5-pyrazolone)-2-thiophenecarboxylic acid hydrazide, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been synthesized and characterized. Single crystal X-ray diffraction analyses indicated that complexes 1–3 exhibit mononuclear octahedral geometry. The spectrophotometric analyses showed that these complexes could bind with herring sperm DNA and bovine serum albumin (BSA). The intrinsic binding constants to HS-DNA were 2.46 × 104 M?1, 2.64 × 104 M?1, and 4.41 × 104 M?1, and the quenching constants to BSA were 1.23 × 106 M?1, 1.85 × 106 M?1, and 2.17 × 106 M?1 for the complexes 1–3, respectively. The complexes have higher cytotoxic activities against HeLa and Eca-109 tumor cells than that of the ligand and cisplatin. Complex 3 shows the highest cytotoxicity for both HeLa and Eca-109, and the IC50 values are 3.35 ± 0.2 μg mL?1 and 7.41 ± 0.07 μg mL?1, respectively. When compared with our previous work, IC50 value of the reported complex CdC20H18N4O3 to Eca-109 cells is 14.18 μg mL?1. We further found that complex 3 inhibits the growth of HeLa cells by inducing apoptosis and arresting the cell cycle during the G0/G1 phase. These results suggest that complex 3 is a potential antitumor drug.

Graphical abstract: Cadmium(ii) complexes with a 4-acyl pyrazolone derivative and co-ligands: crystal structures and antitumor activity
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