Synthesis,characterization and investigation of chelating and antimicrobial activities of 4-((-1h-benzo(D)imidazol-l-yl)methylamino)-2-hydroxylbenzonic acid and its 2- substituted derivatives

Fasasi, Semiudeen Abimbola (2013)

xiv,110

Thesis

This study involved the synthesis, characterization and investigation of the chelating and antimicrobial properties of 4-((-1H-benzo(d)imidazole-l-yl)methylamino)_2-hydroxylbenzoic acid and its 2 substituted derivatives. It was carried out with a view to exploring the wide spectrum of biological properties associated with Benzimidazole nucleus, its derivatives and transition metal complexes. Infrared and Nuclear Magnetic Resonance spectroscopic methods were used to characterize the synthesized ligands. Manganese (II), Copper(II) and Zinc(II) complexes of these ligands were synthesized and characterized by the same methods. The percentage metal composition was determined through complexometric titration. The antimicrobial activities of all the ligands and their transition metal complexes of Mn(II), Cu(II) and Zn(II) were measured for bacteria and fungi pathogens using the agar well diffusion method. The Mannich reaction between 2-Aminobenzimidazole, Methanal and 4-Aminosalicylic acid yielded 4-((2-Amino-1H-benzo(d)imidazol-1-yl)methylamino)-2-hydroxylbenzoic acid (2-Amino BISA). All the compounds and their transition metal complexes were found to be more toxic to fungi than bacteria. Copper complexes had greatest toxicity against the fungi. Toxicity of biocide increased with concentration and Cu(II) complex of 2-AminoBISA was found to be more toxic against Trichophyta Tonsuras, Aspergillus flavus and Candidas albican than the referenced ketofung standard. Conductivities of all complexes were measured in acetonitrile as solvent. They were found to be electrolytes. All the metal complexes were high melting solids and stable in air. All the ligands and their transition metal complexes were soluble in dimethylsulfoxide but insoluble in water. The study concluded that 4-((2-Amino-1H-benzo(d)imidazol-1-yl)methylamino)-2-hydroxylbenzoic acid (2-Amino BISA) could be successfully prepared through the Mannich reaction between 2-Aminobenzimidazole, Methanal and 4-Aminosalicylic acid.

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