carboxy-PTIO

Carboxy-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) is a cell-impermeable small molecule that functions as a potent and specific scavenger of nitric oxide (NO). It reacts stoichiometrically with nitric oxide radicals to generate nitrogen dioxide (NO2) and the corresponding imino nitroxide derivative (PTI). Unlike many other nitric oxide synthase (NOS) inhibitors that prevent the production of NO, carboxy-PTIO directly neutralizes existing NO, making it an essential biochemical tool for differentiating the physiological and pathological effects of NO from other reactive oxygen or nitrogen species. While primarily used as a research reagent, it has been investigated in preclinical models for potential therapeutic applications in conditions involving excessive NO production, such as endotoxic shock, systemic hypotension, and acute renal failure associated with septic shock. It is available in both a free acid form and a potassium salt form, the latter providing improved aqueous solubility.

Other names

2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazol-1-yloxy 3-oxidecarboxy-PTIO potassium salt