Synthesis, Characterization, Crystal Structures, and Urease Inhibition of Copper(II) and Zinc(II) Complexes Derived from Benzohydrazones

Fu-Ming Wang,Guo-Wei Zang,Zhong-Lu You,Li-Jie Li,Tong-Tong Deng

doi:10.17344/acsi.2020.6056

Fu-Ming Wang, Guo-Wei Zang + Show 3 more

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https://doi.org/10.17344/acsi.2020.6056

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Abstract

A new copper(II) complex [Cu(L1)(NCS)(CH3OH)] (1) and a new zinc(II) complex [ZnCl2(HL2)]·CH3OH (2), derived from 4-bromo-N'-(pyridin-2-ylmethylene)benzohydrazide (HL1) and 4-methoxy-N'-(pyridin-2-ylmethylene)benzohydrazide (HL2), were prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy and single crystal X-ray diffraction. The hydrazone HL1 coordinates to the Cu atom in enolate form, while the hydrazone HL2 coordinates to the Zn atom in carbonyl form. Single crystal structural analyses indicate that the hydrazones coordinate to the metal atoms through the pyridine N, imino N, and enolate/carbonyl O atoms. The Cu atom in complex 1 is in square pyramidal coordination, and the Zn atom in complex 2 is in trigonal-bipyramidal coordination. The inhibitory effects of the complexes on Jack bean urease were studied, which show that the copper complex has strong activity on urease.

Highlights

Urease (EC 3.5.1.5; urea amidohydrolase) is a binuclear nickel-dependent hydrolase enzyme, which can be synthesized by numerous organisms, including plants, bacteria, algae, fungi, and invertebrates, and occurs widely in animal and soil.[1]
The synthetic procedure of the hydrazones and the complexes is shown in Scheme 2
The hydrazone HL2 was prepared by the condensation reaction of equimolar quantities of 2-pyridinecarboxaldehyde and 4-methoxybenzohydrazide

Summary

Introduction

Urease (EC 3.5.1.5; urea amidohydrolase) is a binuclear nickel-dependent hydrolase enzyme, which can be synthesized by numerous organisms, including plants, bacteria, algae, fungi, and invertebrates, and occurs widely in animal and soil.[1] Urease enzyme catalyzes the decomposition of urea into ammonia and carbon dioxide in high efficiency,[2] with the rate of catalyzed reaction 1014 times higher than the non-catalyzed reaction.[3] The enzyme possesses harmful effects on both human health and fertile soil.[4] In recent years, Schiff base complexes are reported to have interesting urease inhibitory activities,[5] especially the copper complexes with Schiff bases or hydrazones are promising types of lead structures as urease inhibitors.[6] As a continuation of the work on the exploration of new urease inhibitors, a new copper(II) complex [Cu(L1)(NCS) (CH3OH)] (1) and a new zinc(II) complex [ZnCl2(HL2)] · CH3OH (2), derived from 4-bromo-N’-(pyridin-2-ylmethylene)benzohydrazide (HL1) and 4-methoxy-N’-(pyridin-2-ylmethylene)benzohydrazide (HL2; Scheme 1), were prepared and studied on their urease inhibition activity

Experimental

Results and Discussion

Conclusion