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. Taking the heat off: The 24 curcumin analogues in this study were found to have no toxicity toward mouse bone marrow cells, and some of them showed potent anti‐inflammatory activity by inhibiting LPS‐stimulated TNFα, IL‐6, IL‐1β, PGE2, and NO production in rat macrophages. Pharmacokinetic studies indicated that compound c6 has better bioavailability than curcumin in vivo. Both c6 and c10 may be valuable leads for the development of new anti‐inflammatory agents.