New Schiff base copper (II) and nickel (II) complexes for biomedical applications with reference to SARS-CoV-2 and HIV virus

Abstract

A series of nickel (II) and copper (II) complexes viz. [Ni(L¹)₂](1), [Cu(L¹)₂](2), [Ni(L²)₂](3) and [Cu(L²)₂](4) (Where L¹H= (E)-N-phenyl-2-(thiophen-2-ylmethylene)hydrazine-1-carboxamide, L²H= (E)-2-((3-methylthiophen-2-yl) methylene)-N-phenylhydrazine-1-carbothioamide), have been synthesized and designed as  potential inhibitors against SARS-CoV-2 and HIV-1 virus. The quantum computational calculations are used for structure-property relationship. A detailed structural and non-covalent supramolecular interaction in the ligand (L¹H) is investigated by single crystal structure analysis and computational approaches. Hirshfeld surface analysis was done in the crystal structure of the ligand (L¹H), while 3D topology of the crystal packing is visualized through an energy framework. To find potential inhibitors of the SARS-CoV-2 and HIV-1 virus, molecular docking of the ligands and their corresponding metal complexes with SARS-CoV-2 and HIV-1 virus was performed.  The X-ray crystallographic structure of the main protease of the SARS-CoV-2 (PDB ID: 7VNB) and HIV-1 virus (PDB ID: 1REV) was retrieved from the protein data bank and used as receptor proteins. The molecular docking results showed that Schiff bases and their complexes with SARS-CoV-2 and HIV-1 virus exhibited good binding affinity at binding site of receptor protein. It was observed that the binding affinities of the Schiff bases and metal complexes towards SARS-CoV-2 were comparatively higher than the HIV virus.  This study may offer the new antivirus drug candidates against SARS-CoV-2 and HIV-1 virus.