One-step Synthesis of Ethyl and Methyl Derivatives of Ylidene-Acetate Bonded at Position 5 of Ring 1,3-Thiazole and Evaluation of Their Antibacterial Activities

The emergence of drug resistance in bacteria is a serious threat to human health; therefore, new thiazole derivatives can be good alternatives for common drugs. In this regard, the aim of this study was the one-step synthesis of ethyl and methyl derivatives of ylidene-acetate bonded at position 5 of ring 1,3-thiazole and evaluation of their antibacterial activities. 

From the single-step reaction between thiourea and acetylene decarboxylase derivatives in acetone solvent, the new thiazole structures were derived based on ethyl and methyl, and they were investigated and confirmed by spectroscopic methods, including infrared, carbon nuclear magnetic resonance, and hydrogen proton nuclear magnetic resonance. The antibacterial properties of this isomer were assessed applying minimal inhibitory concentration, minimum bactericidal concentration, and disc diffusion methods. These properties were tested with three repetitions on Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus cereus at a concentration of 1 mg/ml.

The results of the present study showed that the strongest inhibitory effect (R2=250 mg/ml) and highest diameterof the inhibitory zone (R2=34±1/55 mm) of the derivatives used in this experiment were related to Staphylococcus aureus as the same effect of conventional antibacterial drugs.

The results of this study indicated that the new single-step 1,3-thiazole derivatives have very good antibacterial activities against gram-positive bacteria.