Mixed ligand Cu(II) complexes containing o-vanillin-l-tryptophan Schiff base and heterocyclic nitrogen bases: synthesis, structural characterization, and biological properties

• Published in: Journal of coordination chemistry 2015-03, Vol.68 (6), p.1021-1039
• Main Authors: Subha, L., Balakrishnan, C., Thalamuthu, S., Neelakantan, M.A.
• Format: Article
• Language: English
• Subjects: Amino acid Schiff base; Constants; Copper(II) complex; Crystal structure; Deoxyribonucleic acid; DNA binding and cleavage; Electrophoresis; Imidazole; Ligands; Pyridines; Schiff bases; Spectra; Spectroscopy
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2015.1008466

[Cu(L)] (1) and mixed ligand copper(II) complexes [Cu(L)(A)] (2 and 3), where L is the Schiff base derived from o-vanillin and l-tryptophan and A is pyridine (2) and imidazole (3), were synthesized and characterized using conventional and spectral techniques. 2 was structurally characterized using single crystal X-ray crystallography showing that Cu(II) is coordinated through N 2 O 2 donors in a square plane. The EPR spectra of the complexes in frozen solution support a square-based structure. Electrochemical behavior of the complexes has been studied by cyclic voltammetry. The DNA-binding properties of L and 1-3 with calf thymus DNA were investigated by spectral and kinetic methods. For all the complexes, the maximum value of binding constant (0.38 × 10 6 ) was achieved with 3 by spectroscopic titration. The ability of compounds to break pUC19 DNA was checked by gel electrophoresis. The ligand and copper complexes exert cytotoxicity against MCF-7 cell line.