N-hydroxylamine Dapsone

N-hydroxylamine Dapsone is an active metabolite of dapsone (Item No. 23743).¹ It is formed via N-hydroxylation of dapsone by the cytochrome P450 (CYP) isoforms CYP2C8, CYP2C9, CYP2C18, and CYP2C19 in the liver.² N-hydroxylamine Dapsone is cytotoxic to rat hepatocytes (LC₅₀ = 3.6 mM).³ It induces hemolysis in isolated human erythrocytes at a concentration of 100 µM.¹ N-hydroxylamine Dapsone induces phosphatidylserine (PS) exposure on the outer membrane, a marker of apoptosis and platelet activation, and increases the production of reactive oxygen species (ROS) in a concentration-dependent manner in isolated human erythrocytes. It increases thrombus weight in a rat model of surgically induced thrombosis when administered at a single dose of 50 mg/kg or at a dose of 10 mg/kg per day for four days.

WARNING This product is not for human or veterinary use.

1. Bian, Y., Kim, K., An, G.-J., et al. Dapsone hydroxylamine, an active metabolite of dapsone, can promote the procoagulant activity of red blood cells and thrombosis. Toxicol. Sci. 172(2), 435-444 (2019).

2. Winter, H.R., Wang, Y., and Unadkat, J.D. CYP2C8/9 mediate dapsone N-hydroxylation at clinical concentrations of dapsone. Drug Metab. Dispos. 28(8), 865-868 (2000).

3. Veggi, L.M., Pretto, L., Ochoa, E.J., et al. Dapsone induces oxidative stress and impairs antioxidant defenses in rat liver. Life Sci. 83(5-6), 155-163 (2008).