Synthesis and anti-biofilm activity of thiazole Schiff bases

A series of thiazole Schiff bases (SB-1 to SB-7) have been synthesized by reacting 4-( o -methoxyphenyl)-2-aminothiazole and R substituted salicylaldehyde (R = H, 3-Me, 4-Me, 5-Me, 3-OMe and 5-Br) or 2-hydroxy-1-naphthaldehyde under microwave irradiation (a green chemistry approach). The compounds were characterized by spectral (UV–Vis, IR, 1 H NMR, 13 C NMR and GC–MS) and thermal analyses, and tested for the evaluation of anti-biofilm activity against Pseudomonas aeruginosa and anti-bacterial activity against Gram positive ( Bacillus subtilis NCIM 2063) and Gram negative ( Escherichia coli NCIM 2931) bacteria. The scanning electron microscopic images of the bacterial surfaces have shown that the Schiff bases have impeded the biofilm formation at 50–100 μg/mL concentration, without affecting the growth of the cells (and thus behave as antiquorum sensing agents). Confocal laser scanning microscopy has also confirmed the biofilm inhibition. The anti-biofilm and anti-bacterial activities of the Schiff bases are promising in the design and bio-fabrication of medical devices to combat the biofilm-forming pathogenic organisms. Graphical Abstract Graphical abstract of the events occurring in present work