Synthesis, crystal structure and biological activity of two Mn complexes with 4-acyl pyrazolone derivatives

• Two Mn complexes of mononuclear and dinuclear were obtained.
• The interaction of the complex with DNA should be intercalation.
• The protein binding studies confirmed the interactions of the complexes with bovine serum albumin (BSA).
• The complexes possess good anticancer activity.
• Complex 1 inhibit cancer cell's growth by inducing apoptosis.

In order to study the biological activities of transitional metal complexes based on 4-acyl pyrazolone derivatives, two Mn complexes [Mn(HLa)(La)]·(CH3CN)1.5·H2O (1) and [Mn2(Lb)2(μ-EtO)2(EtOH)2] (2) (H2La = N-(1-phenyl-3-methyl-4-benzoyl-5-pyrazolone)-2-thiophenecarboxylic acid hydrazide, H2Lb = N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-2-thiophenecarboxylic acid hydrazide) have been synthesized and characterized. Single crystal X-ray diffraction analysis indicated that 1 is a mononuclear complex and 2 exhibits a dinuclear centrosymmetric structure. Binding of the complexes with Herring Sperm DNA (HS-DNA) showed that complexes 1 and 2 could intercalate to DNA with quenching constant of 5.3 × 104 M−1 and 4.9 × 104 M−1, respectively. The interactions of the complexes with bovine serum albumin (BSA) indicated that complexes 1 and 2 could quench the intrinsic fluorescence of BSA in a static quenching process. Further, the inhibitory effects of the complexes on the cell population growth of the human esophageal cancer Eca-109 cells and the cervical cancer HeLa cells were determined by MTT assay, which indicated that both 1 and 2 significantly inhibited the growth of Eca-109 and HeLa cells, the inhibitory activity of complex 1 is stronger than that of 2. We further observed that complex 1 inhibited the growth of HeLa cells through inducing the apoptosis and arresting cell cycle at S phase. Our results suggested that both complexes 1 and 2 have DNA- and protein-binding capacity and antitumor activity.

Two Mn complexes of 4-acyl pyrazolone derivatives with different structures were constructed and characterized. The DNA binding, protein binding, the inhibitory effects on two cancer cells of complexes 1 and 2 and the apoptosis assay of complex 1 were also investigated.Figure optionsDownload as PowerPoint slide