Synthesis, characterization, antimicrobial activity and dyeing potential on leather using bromamine-derived anthraquinone acid dyes

Abstract

Three different anthraquinone acid dyes were synthesized by condensation of bromamine acid with p-acetamido aniline, p-aminophenylacetic acid and p-benzaldehyde to obtain two blue and one green crystalline solid dyes. The synthesized dyes were fully characterized using UV-Visible, FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. The results of the antimicrobial screening of the dyes as indicated by the zone of inhibition (ZOI) showed that, all the synthesized dyes have significant activities against the test microbes compared to the standard drugs used, except Candida albicans which was resistant against all the synthesized dyes. The result of minimum inhibitory concentration (MIC) showed that, at concentrations of 100μg/ml and 50 μg/ml of dyes I and II, the growth of Escherichia coli and Salmonella typhi were inhibited, while for dye III, 25 μg/ml was the minimum concentration required to inhibit the growth of Staphylococcus aureus, Baccillus subtillis and Escherichia coli. Furthermore, investigating the minimum bactericidal concentration (MBC) showed that, at a lower concentration of 25 μg/ml of dye III Staphylococcus aureus, Bacillus subtilis and Escherichia coli were killed compared to 50 μg/ml of dyes I and II required to completely kill Bacillus subtilis, Salmonella typhi and Staphylococcus aureus. The results for dyeing and fastness properties on leather showed that, the synthesized dyes gave excellent homogeneity of coloration on leather. A remarkable degree of evenness indicates good penetration and affinity of these dyes to fabrics. Thus, the synthesized dyes possess excellent light and washing fastness rating of 6 and 4 hence, gave good dyeing on leather.