Celecoxib prodrugs possessing a diazen-1-ium-1,2-diolate nitric oxide donor moiety: Synthesis, biological evaluation and nitric oxide release studies

A new class of anti-inflammatory (AI) cupferron prodrugs was synthesized wherein a diazen-1-ium-1,2-diolato ammonium salt, and its O2-methyl and O2-acetoxyethyl derivatives, nitric oxide (NO) donor moieties were attached directly to an aryl carbon on a celecoxib template. The percentage of NO released from the O2-methyl and O2-acetoxyethyl compounds was higher (18.0-37.8% of the theoretical maximal release of one molecule of NO/molecule of the parent compound) upon incubation in the presence of rat serum, relative to incubation with phosphate buffer saline (PBS) at pH 7.4 (3.8-11.6% range). All compounds exhibited weak inhibition of the COX-1 isozyme (IC50 = 5.8-17.0 μM range) in conjunction with weak or modest inhibition of the COX-2 isozyme (IC50 = 1.6-14.4 μM range). The most potent AI agent 5-[4-(O2-ammonium diazen-1-ium-1,2-diolato)phenyl]-1-(4-sulfamoylphenyl)-3-trifluoromethyl-1H-pyrazole exhibited a potency that was about fourfold and twofold greater than that observed for the respective reference drugs aspirin and ibuprofen. These studies indicate that use of a cupferron template constitutes a plausible drug design approach targeted toward the development of AI drugs that do not cause gastric irritation, or elevate blood pressure and induce platelet aggregation that have been associated with the use of some selective COX-2 inhibitors.