Synthesis, spectroscopic investigation, fluorescence, anticancer, antioxidant and DNA cleavage studies of coumarin hydrazone metal complexes

Abstract

Bivalent transition metal complexes of manganese, cobalt, nickel, copper and zinc were synthesized from coumarin derivatives and characterized by various spectral studies. The analytical data obtained from Infrared, Nuclear Magnetic Resonance and Ultra-Violet studies confirmed that ligand binds with the metal ion via azomethine nitrogen, oxygen of the carbonyl group and the deprotonated oxygen of coumarin moiety.Thermogravimetric analysis confirmed that the presence of coordinated water molecules in the metal complexes except zinc complex.The Electron Spin Resonance spectrum showed the covalent character of copper(II) complex. The X-ray Diffraction pattern revealed the crystalline nature of nickel and manganese complexes. Fluorescence spectra of ligand and metal complexes were recorded. It is found that the fluorescence intensity of metal complexes decreased in comparison with ligand. The anticancer activity has been analyzed against the two cell lines viz.Human Breast cancer cell line (MCF-7) and Leukemia Cancer Cell Line (K-562). Studies showed that the cobalt complex has greater inhibition activity against the above two cell lines. The ligand and metal complexes were also subjected to antioxidant activities. The ligand exhibited higher free radical scavenging activity than the metal complexes. From the DNA cleavage study, it is confirmed that the nickel complex has cleaved DNA completely in the presence of Hydrogen peroxide.

Keywords

• Schiff base
• Coumarin moiety
• Isatin monohydrazone
• Fluorescence spectra
• Anticancer activity
• Antioxidant activities