SYNTHESIS, CRYSTAL STRUCTURES AND UREASE INHIBITION OF ZINC(II) AND COPPER(II) COMPLEXES DERIVED FROM 2-AMINO-N’-(1-(PYRIDIN-2-YL)ETHYLIDENE)BENZOHYDRAZIDE

Abstract

Two mononuclear zinc(II) and copper(II) complexes, [ZnBr(HL)(NCS)] (1) and [CuL2] (2), where HL and L are the ketone and enolate forms of 2-amino-N’-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL), have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, as well as single crystal X-ray diffraction studies. The Zn atom in complex 1 is in distorted square pyramidal coordination, with the pyridine N, imino N and carbonyl O atoms of the hydrazone ligand HL and the N atom of the thiocyanate ligand in the basal plane, and with the Br atom at the apical position. The Cu atom in complex 2 is in distorted octahedral coordination, with the pyridine N, imino N and enolate O atoms of one hydrazone ligand L, and the imino N atom of the other hydrazone ligand L in the equatorial plane, and with the pyridine N and enolate O atoms of the other hydrazone ligand L at the axial positions. The hydrazone and the complexes have been assayed for their Jack bean urease activity. As a result, the copper complex has effective urease inhibitory activity with IC50 = 11.9 ± 1.3 μmol L–1. Molecular docking study was performed to investigate the interaction between the complex molecule and the enzyme.