Synthesis, characterization and antimicrobial activity of peanut skin extract-azo-compounds

Abstract

Peanut skin extract, an agro-waste and a source of flavonoids has been extracted from peanut skin and employed as a precursor for the synthesis of novel azo compounds and metal complexes. The new ligand, peanut skin extract-azo-compound, was synthesized under suitable experimental conditions by diazotization of aniline and coupling with an alkaline solution of peanut skin extract. The reaction of the ligand with metal chlorides of iron and manganese under reflux yielded novel azo metal complexes. The yields of the compounds ranged from 42% to 95%. All compounds were coloured, insoluble in water but soluble in methanol, ethanol, acetone and ethyl acetate. Morphology and composition of ligands and metal complexes were corroborated by spectroscopic techniques including Fourier transform infrared spectroscopy, scanning electron microscope-energy dispersive spectrometry and UV-visible spectroscopy. The azo complexes were found to possess potent antimicrobial activities against E. coli (gram-negative bacteria) and Staphylococcus aureus (gram-positive bacteria) and hence recommended for application as antimicrobial agent, and corrosion inhibitors in anti-corrosion paints and pigments for surface coatings.