Antimicrobial/antioxidant and cytotoxicity activities of some new mercury(II) complexes

Document Type : Research Article


1 Department of Chemistry, Yasouj University, Yasouj 7591874831, Iran

2 Department of Chemistry, Yasouj UNiversity, Yasouj 7591874831 Iran

3 Department of Animal Sciences, Yasouj University, Yasouj 7591874831, Iran

4 Medicinal Plants Research Center, Yasuj University of Medical Sciences, Yasuj, I.R. Iran

5 Department of Basic Sciences, Yasooj branch, Islamic Azad University, Yasooj, Iran


In this paper, a new aprotic N2O2-tetradentate Schiff base ligand and its mercury complexes were synthesized with a general formula of HgLX2 (X is Cl−, Br−, I−, N3−, NO3− and SCN−) and characterized by physical and spectral techniques such as IR, UV-Visible, 1H NMR, 13C NMR, ESI/MASS, molar conductivity, thermal analysis and melting point. In addition, nanostructured HgLI2 and HgLBr2 complexes were also synthesized and confirmed using SEM, EDX and XRD techniques. Thermal analysis of the ligand and complexes showed that these compounds decompose in 2-3 steps. Moreover, some thermo-kinetics activation parameters of the compounds were calculated at all the thermal decomposition steps. The biological properties of synthesized compounds were tested against two gram-positive and two Gram-negative bacteria. Also, Aspergillus oryzae and Candida albicans were selected for antifungal screening of the compounds. Further, the bactericidal effects of the compounds were depicted by SEM images of treated bacteria by the ligand and some mercury complexes. The ability of DNA cleavage of N2O2-tetradentate Schiff base ligand and its complexes was investigated by the agarose gel electrophoresis method. The results showed that Schiff base mercury complexes had higher antibacterial/antifungal activity as compared with the free ligand. HgLX2 compounds also showed a greater ability to cleavage of DNA than free ligand. Furthermore, the cytotoxicity properties of the ligand and some HgLX2 (X=Cl−, Br− and I−) complexes were evaluated against the PC3 cancer cells line by using MTT bioassay and nitric oxide level measurement as compared with cisplatin. Finally, the antioxidant activities of the titled compounds were measured by DPPH and FRAP methods.


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