Synthesis,biological evaluation of certain pyrazolo[3,4-d]pyrimidines as novel anti-inflammatory and analgesic agents

In the present study, a series of pyrazolo[3,4-d]pyrimidin-4(5H)-ones linked at 5-position to thiazoline or thiazolidinone ring systems through imino linkage (5–8) was designed and synthesized. The compounds were assessed for their anti-inflammatory activity and analgesic in vivo. Also, their ability to inhibit ovine COX-1/COX-2 isozymes was evaluated using in vitro cyclooxygenase (COX) inhibition assay. The newly synthesized compounds 7, 8d, and 8e showed potent anti-inflammatory and analgesic activity. Moreover, compound 7 displayed preferential COX-2 inhibitory potency (IC₅₀ = 0.53 µM and COX-2 selectivity index = 10.07) which is more potent than the standard drug meloxicam. Interestingly, the tested compounds showed excellent gastrointestinal safety profile and were well tolerated by experimental animals with high safety margins than the reference drug meloxicam.