Synthesis of thiazole-based substituted piperidinone oximes: Profiling of antioxidant and antimicrobial activity

The synthesis of novel thiazole-based piperidinone oximes and screening of their antioxidant and antimicrobial activity are described. The obtained results revealed that the electronic effects of active substituents at C-4 terminals of phenyl rings on either side of piperidinone skeleton, as well as at 2-hydrazinyl thiazole, played a major role in development of antioxidant and antimicrobial activity. Antioxidant activity seems to be based also on radical dissipating ability of the thiazole ring. The nucleophilic character of sulfur in thiazole and lipophilic nature of piperidinone skeleton substantially influenced the observed antimicrobial activity of thiazole-based piperidinone oximes. Among the synthesized compounds, 2,6-bis(4-hydroxy-3-methoxyphenyl)-1-methylpiperidin-4-one O-(2-(2-(4-hydroxy-3-methoxybenzylidene)hydrazinyl)thiazol-4-yl) oxime exhibited excellent antioxidant activity whereas compound 2,6-bis(4-chloro phenyl)-1-methylpiperidin-4-one O-(2-(2-(4-nitrobenzylidene)hydrazinyl)thiazol-4-yl)oxime emerged as an outstanding antimicrobial agent.