New thiazole-based bis(Schiff bases) linked to arene units as potential MRSA inhibitors

Abstract

A new series of thiazole-based bis(Schiff bases) attached to different arene units were efficiently prepared using a three-component tandem protocol. The proposed protocol involved the reaction of aromatic aldehydes, thiosemicarbazide, and bis(α-haloketone) to produce the desired products. The target hybrids were formed by an initial thiosemicarbazone formation in ethanol at 80 °C for 120–150 min, followed by triethylamine-mediated Hantzsch thiazole synthesis in dioxane at 100 °C for 150–180 min. The new hybrids were screened against diverse bacterial strains. The hybrids attached to p-Cl, p-Br, and p-Me had more effective efficacy than ciprofloxacin against S. aureus, and E. coli strains, while they had comparable efficacy to ciprofloxacin against S. mutans, and K. pneumonia strains. Their MIC/MBC values ranged between 1.3–3.2 and 2.6–6.5 µM, respectively, against the previous strains. Additionally, they displayed more effective MRSA inhibitory activity than linezolid with MIC/MBC values in the range of 3.0–21.3 µM.