Spectroscopic studies, DFT calculations, cytotoxicity activity, and docking stimulation of novel metal complexes of Schiff base ligand of isonicotinohydrazide derivative

In this elucidation, the reactivity of isonicotinohydrazide derivative ( 3 )( L ) was reacted with the nitrate salts of Cr( III ), Fe( III ), Co( II ), Ni( II ), Cu( II ), and Zn( II ) to afford the corresponding stable metal coordination compounds. The synthesized metal coordination compounds were confirmed through physicochemical and analytical analysis such as elemental analysis, UV‐Visible, FT‐IR, TGA, Mass, 1 H NMR, XRD, magnetic, and molar conductance analysis. All complexes exhibit distorted octahedral geometry except Zn( II ) complex which has a distorted tetrahedral arrangement. Both the thermal stability and the kinetic parameter for all complexes were elucidated via TGA analysis and Coats‐Redfern method. XRD study suggested that the complexes have a partially amorphous structure which was further confirmed by calculating the crystallinity index. Moreover, the synthesized metal complexes exhibited excellent cytotoxicity activity contra lung cancer cells ( A549 ) and liver cancer cells ( HepG2 ) using neutral red uptake assay. The complexes of Fe( III ), Ni( II ), and Zn( II ) showed higher cytotoxic effect than doxorubicin against A549 and HepG2 cells for 24 h incubation. Furthermore, the Cr( III ), Co( II ), Zn( II ), and Cu( II ) coordination compounds showed more inhibitory influence when treated with A549 and HepG2 cells for 48 h incubation. The biological studies of these complexes were confirmed through molecular docking studies with different proteins such as ( PDB ID : 2ITO) and ( PDB ID : 5H38) and showed low binding energy and shortage bond length with different amino acids. Also, computational calculations of all metal complexes were carried out utilizing DFT/B3LYP/LANL2DZ basis set to detect the FMO, ESP, MEP, and physical descriptor's of them and confirms their reactivity.