Synthesis and pharmacological evaluation of pyridinyl-1,3,4-oxadiazolyl-ethanone derivatives as antimicrobial, antifungal and antitubercular agents

摘要

Abstract Nicotinic acid was converted into different substituted acetylated nicotinic acid derivatives by sequential transformation involving formation of hydrazide, Schiff’s base and finally acylated oxadiazole derivatives. The synthesized compounds were characterized by spectroscopic techniques and evaluated in vitro for the antimicrobial, antifungal, as well as antitubercular activity. Among all the synthesized derivatives, compounds 6b , 6d , 6e , 6g , and 6j demonstrated excellent antimicrobial activity on Bacillus subtilis . The compounds 6d , 6j and compounds 6b , 6f , 6h , and 6i exhibited maximum zone of inhibition against fungi Candida albicans as well as Aspergillus niger , respectively at the concentration of 500?μg/mL. The antitubercular activity exhibited by 6f , 6g , and 6d with minimum inhibitory concentration (MIC) values of 1.2, 3.1, and 7.8?μg/mL, respectively. The synthesized compounds were studied by molecular docking through Autodock Vina to evaluate their interaction at respective proteins. Further the effect of synthesized derivatives on surface morphology of human erythrocytes as well as hemolysis was also evaluated. The results demonstrated lesser extent of hemolytic toxicity. Graphical abstract