Studies on new Schiff base complexes synthesized from d10 metal ions: Spectral, conductometric measurements, DFT and docking simulation

Abstract

New Cd(II), Hg(II), Zn(II), UO2(II) complexes were prepared from cyclohexanone-[N-(3-hydroxy-2-naphthoyl)]hydrazone (H2CHNH) ligand by using ball milling technique. The formed compounds were elucidated by spectral (IR, NMR, SEM, EDX, Mass), analytical and conformational techniques. Schiff base ligand exhibited variable binding modes towards the metal ions within 1:1 M ratio mostly. Tetrahedral configuration was proposed for all d10 coordination systems except UO2(II) complex which basically desired to octahedral geometry. Conductometric measurements estimated association (KA, ΔGA) and formation constants (Kf and ΔGf) for Cd(II)- H2CHNH complex in solution. DFT/B3LYP computation was applied to optimize structures of compounds and extract important physical characteristics. In-vitro assay was applied to investigate antimicrobial, antioxidant and antitumor activity of new synthesizes. Best antioxidant and antitumor activity was recorded with Zn(II) complexes. For clarification, in-silico assay was executed by drug-like procedure as well as MOE-docking approach. Pharmit link was used to search on the most fitted drug-like to Zn(II) complexes. After 1,602,203 hits in MolPort library, the drug numbered by MolPort-000–810-252 was the most fitted one. MOE-docking was utilized with respect to Zn(II) complexes towards liver cancer cell proteins (3 h80, 4ndn & 8adh). [Zn(HCHNH)2].2H2O complex reveals high docking score in true interaction poses. Limited allosteric binding was recorded from O11, N15 and O42 sites towards amino acid residues or dummies. Finally, two Zn(II) complexes may be promising in controlling free radicals or liver cancer cells.