Microbiocidal Studies of Some Azo Dyes

Abstract

Microbiocidal potential of some azo dyes has been studied. Polydentate azo dyes viz. 1-(2’-carbo xyphenylazo)-2-naphthol, 5-(2’-carboxyphenylazo)-8-hydroxyquinoline, 5-(2’-carboxyphenylazo)salicylic acid and 4-(2’-carboxyphenylazo)resorcinol were synthesized and characterized by elemental analysis, infrared (FTIR) and 1H NMR spectral studies. The dyes were screened for antibacterial sensitivities against the Gram positive bacteria Staphylococcus aureus and Gram negative bacteria Enterobacter aerogenes and Escherichia coli at four concentrations of the dyes viz. 0.5, 1.0, 1.5 and 2.0 mg/ml, in acetone. Results revealed a high to low potency of the dyes as antibacterials. 5-(2’-carboxyphenylazo)salicylic acid and 4-(2’-carboxyphenylazo) resorcinol in the concentration range of 1 to 2mg/ml, were found to be more potent in inhibiting the bacterial growth uniformly towards all the three bacteria. A possible role of salicylate or resorcinol moieties, in addition to azo group of these dyes in their higher microbiocidal activities may be envisaged. These azo dyes may, thus, be of medicinal value.