Synthesis of Novel Quinoline–Benzoxazolinone Ester Hybrids: In Vitro Anti-Inflammatory Activity and Antibacterial Activity

A series of novel quinoline-benzoxazolinone ester hybrids were synthesized characterized and assessed for their in vitro anti-inflammatory and antibacterial activity. The in vitro anti-inflammatory activity was executed using protein denaturation assay, proteinase inhibitory assay and human red blood cell membrane stabilization assay. Most of the compounds exhibited potential anti-inflammatory activity. Compound (2-oxobenzo[ d ]oxazol-3(2 H )-yl)methyl-2-(thiophen-2-yl)quinoline-4-carboxylate showed a better anti-inflammatory activity than the standard drugs diclofenac sodium and indomethacin. Furthermore, antibacterial activities of the synthesized compounds were evaluated using resazurin microtiter assay (REMA) and were compared with a positive drug standard chloramphenicol. The compounds demonstrated moderate to potent antibacterial activity. (2-Oxobenzo[ d ]oxazol-3(2 H )-yl)methyl-2-(3,4-dimethoxyphenyl)quinoline-4-carboxylate and (2-oxobenzo[ d ]oxazol-3(2 H )-yl)methyl-2-(2-chlorophenyl)quinoline-4-carboxylate displayed excellent activity against all bacterial strains in comparison to standard chloramphenicol. Moreover, cytotoxicity was performed on MDCK cells using MTT assay and it was found that none of the synthesized derivatives possessed any cytotoxicity.