Synthesis And Biological Activity Of A Novel Non-steroidal Anti-inflammatory Drug ML4000

Objective: To synthesize the nitric-oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) ML4000 with a cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) dual inhibitor licofelone (ML3000), and evaluate its biological activity. Methods: ML4000 was synthesized through nine steps.2-Benzyl-4,4-dimethyl-1-pyrroline was prepared with 3,3-dimethyl propanediol as the starting material via condensation, ring-opening and substitution reaction, and then after addition reaction with benzylmagnesium chloridethe and ring-forming reaction withα-bromo-4-chloroacetophenone the key intermediate substituted pyrrolizinone was obtained. ML3000 was synthesized from the pyrrolizinone by the Friedel-Crafts reaction with oxalyl chloride and Huangminglong reaction sequentially. The target product of ML4000 was finally obtained from the sodium salt of ML3000, 1,4-dibromobutane and AgNO3 through condensation. Biological activity tests included the preliminary in-vivo metabolism of ML4000 (po), evaluation of anti-in?ammatory activity using the xylene-induced mice ear edema model and carrageenan-induced rat paw oedema model, observation of gastric mucosal surface bleeding and ulcers, and fecal occult blood after continuous oral administration, and determination of NO release from ML4000 (po).Results: ML4000 was synthesized with a yield of 11% and confirmed by IR, MS,¹H NMR, ¹³C NMR and elemental analysis. In rats,the metabolite ML3000 of ML4000 (10mg·kg^-1, po) was detected after 0.25h;it was found to be equipotent to ML3000 in anti-inflammatory activity;no gastrointestinal bleeding and ulcers was found in rats at 60mg·kg^-1 po for consecutive 14 days,significant increase of NO on the serum and gastric mucosa after 1 h at 60mg·kg^-1 po。Conclusion: The ML4000 chemical structure consists of one ML3000 molecule covalently bound to one NO-donating moiety, butanediol mononitrate. In vivo, the ML4000 molecule is metabolized to the NSAID, ML3000, and NO. The preliminary bioassay showed that it has good anti-inflammatory activity and gastrointestinal tolerability and significant NO releasing activity。...