Synthesis, characterization, and DNA cleavage study of dehydroacetic acid based tridentate Schiff’s base and its metal complexes of first transition series

In search of novel chemical nucleases the synthesis of dehydroacetic acid based tridentate hydrazone Schiff base and its colored complexes with Co(II), Ni(II), Cu(II), Mn(II), and Zn(II) has been achieved. All synthesized compounds were screened for their DNA cleavage potential using the plasmid DNA. The hydrazone Schiff base was synthesized via a condensation reaction between acetic acid hydrazide and dehydroacetic acid. Further, this novel ligand was allowed to react with different transition metal salts in 1:1 and 1:2 ratios, respectively to synthesize metal complexes with a different ligand to metal stoichiometry. All the compounds were characterized on the basis of various spectroscopic techniques. 1H NMR data of complexes showed the coordination of enolic oxygen atom with subsequent lose of proton and IR data shows that the participation of carbonyl oxygen atom of ligand in coordination with metal ion. UV–Visible data reveals the square planner and octahedral geometry of the synthesized metal complexes. Mass spectrum confirms the formation of both 1:1 and 1:2 metals to ligand stoichiometry. Metal complexes were found to exhibit good level of DNA cleaving activities at concentration of 10 μg μl−1.