Biological evaluation, synthesis and characterization of transition metal complexes of N-Methyl o and p-substituted benzohydroxamic acids

Bibi Shireen

doi:10.19045/bspab.2020.90235

Abstract

The four new transition metal complexes as Copper (II), Nickel (II), Cobalt (II) and Cadmium (II) of N-Methyl benzohydroxamate compounds have been prepared by refluxing 2:1 molar ratio of the o- and p-substituted hydroxamic acid ligands along with transition metal salts in hot toluene, using a Dean Stark water separator. The elemental analysis and FT-IR Spectroscopic technique were used to characterizing the hydroxamic acid ligands and its transition metal complexes. Spectroscopic analysis exhibits that the hydroxamic acid ligand behaves as a bidentate chelator and coordinating with metal atom through carbonyl oxygen and deprotonated hydroxyl group. The antibacterial and antifungal activity of hydroxamic acid ligands and their transition metal complexes were evaluated. Transition metal complexes display stronger antibacterial activity than their ligands because of the chelating property of ligands to metal ions and as a result chelation increases the lipophilicity of the complexes. However, ligands and their transition metals complexes did not display any antifungal activity against the Aspergillus Niger (fungus). This study shows that several transition metal complexes are successfully synthesized and these complexes exhibit high antibacterial activity with less toxicity. This research encourages further synthesis of transition metal complexes and the invention of future metal based drugs. Keywords: Agar well method; Antibacterial activity; Antifungal activity; Coordination; FT-IR; Hydroxamic acids; Metal complexes http://dx.doi.org/10.19045/bspab.2020.90235

Highlights

These compounds are the derivates of bothHydroxamic acids having a general formula hydroxylamines and carboxylic acids [1].RCONHOH derived from oxoacids by Hydroxamic acids play an essential role in substituting the hydroxyl (OH) by NHOH.many biochemicals, industrial, analytical pharmaceutical fields
This study shows that several transition metal complexes are successfully synthesized and these complexes exhibit high antibacterial activity with less toxicity
The transition metal complexes have started the production of new metal-based drugs having pharmaceutical application and offers therapeutic opportunities [12, 13]

Summary

Introduction

Hydroxamic acids having a general formula hydroxylamines and carboxylic acids [1]. RCONHOH derived from oxoacids by Hydroxamic acids play an essential role in substituting the hydroxyl (OH) by NHOH. Hydroxamic acid moieties has recently been imparted for their potential use as, tumor growth, inhibitors of hypertension, asthma, inflammation and other pharmaceutical application [7, 8]. These bidentate hydroxamic acid ligands are behave as a chelated ligand toward metals atoms as copper, nickel, cadmium, iron [1]. The transition metal complexes with various ligands play a major role in the form of numerous chemical compounds [9]. These diverse transition metals as, zinc copper, nickel and iron display important role in many biological systems [10] and show strong antibacterial activity against the different pathogenic microorganisms. Antibacterial and antifungal activity of these compounds has been determined

Materials and methods

Conclusion