Synthesis, Characterization and Antibacterial Evaluation of Novel Β- Lactam and Thiazolidin-4-One Derivatives Having Thiadiazinyl Ring

Abstract

Since ancient times, several heterocyclic scaffolds have been recognized as possessing a wide spectrum of anti-infectious pharmacological properties. The present work aimed to synthesize and to perform antibacterial screening of some novel heterocyclic derivatives of thiadiazinyl β-lactam and thiazolidin-4-one. Cyclization of thiosemicarbazide with cyclohexanone and substituted aromatic aldehydes leads to the formation of Schiff bases, which form thiazolidinone derivatives upon reaction with thioglycolic acid in the presence of a catalytic amount of ZnCl2. Lactam derivatives were synthesized by the cyclization of Schiff bases with chloroacetyl chloride in presence of triethyl amine. The synthesized derivatives 2a (MIC 25 µg/ml), and 3f (MIC 25 µg/ml) with 4-OH, 3-OCH3, and o-hydroxy substituents, respectively, exhibit good activity against S. aureus, while compound 2c containing p-nitro substituent was found to be the most active (MIC 12.5 µg/ml) against B. subtilis. In Gramnegative bacterial strains, compound 3b (o-chloro) was extremely potent (MIC 12.5 µg/ml) against P. pneumonia while compound 2d containing the p-hydroxy group shows excellent activity (MIC 12.5 µg/ml) against E.coli.