Synthesis and anti-inflammatory activity of novel firocoxib analogues with balanced COX inhibition

The adverse effects caused by nonselective and selective cyclooxygenase-2 (COX-2) inhibitors remain a challenge for current anti-inflammatory medications. A balanced inhibition of COX-1/-2 represents a promising strategy for the development of novel COX-2 inhibitors. In this study, we present the design and synthesis of a novel series of firocoxib analogues incorporating an amide bond to facilitate essential hydrogen bonding with amino residues in COX-2. The synthesized analogs were evaluated for their inhibitory activity against both COX-1 and COX-2 enzymes. Among them, compound 9d demonstrated potent and balanced inhibition. Inhibition of COX enzymes by 9d in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages resulted in the suppression of the NF-kappa B signaling pathway to reduced expression of pro-inflammatory factors such as inducible nitric oxide synthase (iNOS), COX-2, nitric oxide (NO), and reactive oxygen species (ROS). The remarkable in vitro anti-inflammatory activity exhibited by 9d positions it as a promising candidate for further development as a novel lead compound for inflammation treatment.