The synthesis, characterization, DNA/protein interaction, molecular docking and catecholase activity of two Co(II) complexes constructed from the aroylhydrazone ligand

Abstract Two Co(II) complexes, Co(BBH)phenMeCN (1) and Co(BSH)phenMeCN (2) (HBBH = benzophenone benzoyl hydrazone, HBSH = benzophenone salicylylhydrazone ligand and phen = 1,10-phenanthroline) were prepared and characterized by single X-ray crystallography. The investigation of the complexes binding with herring sperm DNA (HS-DNA) revealed that stronger binding interaction exists between the complexes and HS-DNA compared to the corresponding free ligands. And both complexes can bind to DNA through intercalation of the phenyl rings between adjacent base pairs in the double helix. Meanwhile, bovine serum albumin (BSA) binding studies reveal the complexes can effectively interact with BSA and change the secondary structure of BSA. Superoxide dismutase (SOD) mimic activity of the complexes was investigated and the results showed that complex 2 showed a stronger radical scavenging potency against O2.- radical with an IC50 value of 16.10 μM. The catecholase-like activity of both complexes has been investigated with 3,5-di-tert-butylcatechol (3,5-DTBC) as the substrate in methanol solution under completely aerobic conditions. The catalytic reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers (kcat) of 34.14 h−1 and 30.36 h−1 for complex 1 and complex 2, respectively.