Abstract:
Benzimidazole and its derivatives found variety of biological activities, for the searching of its potent antiinflammatory analogues, we synthesized four novel 4-(2-keto-1-benzimidazollinyl) piperidine derivatives (Q1 to Q4) by
refluxing piperidine with substituted imidazole and subjected to in-vitro anti-inflammatory (ROS, NO) and antibacterial
activities, structures were elucidated using spectroscopic techniques. Results revealed that compound Q1 showed most
effective anti-inflammatory activity with IC50 7.6±1.3 µg/ml compared with standard Ibuprofen having IC50
11.2±1.9µg/mL. Compound Q3 showed good activity for Nitrite accumulation by stimulating macrophages test similar
to standard NG Methyl L-arginine acetate with IC50 value 24.2±0.8µg/mL. The antibacterial activity of these compounds
were evaluated against selected Gram+ve E. faecalis, C. diphtheriae, S. aureus and Gram -ve organism E. coli,
Enterobacter aerogenes and P. aeruginosa. Synthesized compounds showed low to moderate level of antibacterial
activity Q1 showed the highest antibacterial activity against Enterococcus faecalis and Escherichia coli with zone of
inhibition 18mm and Q3 showed highest activity against Corynebacterium diptheriae (ZOI:18mm). Structure-activity
relationship (SAR) study revealed that among all the synthesized compounds unsubstituted naphthalene (Q1) and phenyl
(Q3) ring containing derivatives were most potent.
