Aryl azo 5-arylidene-2,4-thiazolidinone dyes as novel antioxidant and antibacterial compounds

In the present study, nine bis-azo dyes based on 5-arylidene-2,4-thiazolidinone were obtained in two steps, using Knoevenagel condensation and azo coupling reactions. The structure of the dyes was confirmed on the basis of spectral data. Analysis of spectroscopic data shows that there is equilibrium between the azo and hydrazone tautomers for all dyes in solutions. Investigation of antioxidant activity of compounds was carried out by 2,2-dipheny l-1-picrylhydrazyl DPPH and ferric reducing antioxidant power FRAP methods. The antibacterial activity towards three Gram negative and two Gram positive bacteria was also investigated. The activity data show that the synthesized dyes 3a-i have promising antibacterial activity, comparable with their precursor 1.