Synthesis, characterization, and pharmacological aspects of metal(II) complexes incorporating 4-[phenyl(phenylimino)methyl]benzene-1,3-diol

Abstract

New metallointercalators (1a–1e) have been synthesized using the Schiff base, 4-[phenyl(phenylimino)methyl]benzene-1,3-diol and metal(II) ions, viz. Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). They are characterized by analytical and spectral methods. Elemental analyses and molar conductance values reveal that the Schiff base metal(II) complexes have 1 : 2 stoichiometry and are non-electrolytes. The Schiff base (HL) binds with M(II) ions through azomethine and deprotonated phenolic groups. Thermal studies reveal the presence of water in 1a–1c. Powder X-ray diffraction and SEM studies show that all the complexes are microcrystalline with homogenous morphology. In vitro biological activities of HL and 1a–1e have been screened against bacteria and fungi by well diffusion technique, revealing that these complexes are good antimicrobial agents against various pathogens. The complexes exhibit better biological activities than HL. Complex 1d binds with Calf thymus DNA through intercalation and weak covalent interactions. The oxidative cleavage of 1a–1e with pUC 19 DNA has also been explored. The results indicate that they bind to DNA through intercalation and are efficient metallointercalators and cleaving agents.

Graphical Abstract

The 4-[phenyl(phenylimino)methyl]benzene-1,3-diol Schiff base metallointercalators act as efficient DNA binding and cleaving agents. All the complexes are in vitro biological and antioxidant activators. Cu(II) complex is found to be efficient intercalator than other chelates.

Keywords:

• Benzophenone
• Schiff base metal(II) complexes
• Metallointercalators
• Biological activity
• DNA cleavage

Acknowledgements

We express our sincere thanks to the College Managing Board, Principal, and Head of the Department of Chemistry, Devanga Arts College, Aruppukottai and VHNSN College, Virudhunagar for providing research facilities. They express their gratitude to SAIF, IIT Madras, IIT Bombay, and Punjab University for recording NMR, EPR, and FAB-mass spectra, respectively, and STIC, Cochin for TGA/DTA and SEM studies.