Evaluation of anti-inflammatory and antibacterial potential of newly synthesized 4-(2-Keto-1-benzimidazollinyl) derivatives of piperidine.

Benzimidazole and its derivatives found variety of biological activities, for the searching of its potent anti-inflammatory 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 IC ₅₀ 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 N_G 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.