Synthesis and Evaluation of Anti‐inflammatory N‐Substituted 3,5‐Bis(2‐(trifluoromethyl)benzylidene)piperidin‐4‐ones

A total of 24 N-substituted 3,5-bis(2-(trifluoromethyl)benzylidene)piperidin-4-one derivatives were synthesized via aldol condensation, and their anti-inflammatory activities were evaluated. These compounds were found to have no significant cytotoxicity against mouse bone marrow cells in vitro. However, some compounds, such as c6 (N-(3-methylbenzoyl)-3,5-bis-(2-(trifluoromethyl)benzylidene)piperidin-4-one) and c10 (N-(2-chlorobenzoyl)-3,5-bis-(2-(trifluoromethyl)benzylidene)piperidin-4-one), displayed potent anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), IL-1β, prostaglandin E2 (PGE2), and nitric oxide (NO) production in RAW 264.7 cells. Treatment with c6 or c10 at 2.5 or 10 mg kg−1 significantly decreased the paw edema induced by carrageenan in rats, and the anti-inflammatory effects of these compounds were found to be better than those of celecoxib or indomethacin as well as their parent compound C66 (2,6-bis-(2-(trifluoromethyl)benzylidene)cyclohexanone). Pharmacokinetic analysis indicated that c6 has better bioavailability than curcumin. Therefore, these compounds may be valuable leads for the development of new anti-inflammatory drugs.