Biosensitive metal chelates from curcumin analogues: DNA unwinding and anti-microbial evaluation

Few curcumin based metallointercalators having the amino acid (cysteine) have been synthesized and characterized by IR, UV–vis, NMR, EPR and magnetic susceptibility measurements. The data show that the complexes have the composition of ML type. The electronic absorption spectral data of the complexes suggest a square planar geometry around the central metal ion. The interpretation of spectroscopic and magnetic moment data suggests that the ligand is coordinated via ketimine, carbonyl and enolic oxygen of curcumin analogue. The interaction of the complexes with DNA is explored using absorption spectra, cyclic votammetric, viscosity measurements and gel electrophoresis technique. The data reveal that the complexes are strong intercalators and potential nucleases as compared to curcumin based free ligand. The antimicrobial activities of the ligand and its complexes are also explored and it is found that the complexes exhibit better activity against bacteria and fungi than the ligand.