Sulfaphenazole (Standard) is the standard substance of Sulfaphenazole, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Sulfaphenazole (Plisulfan) is an inhibitor of CYP2C9 (Ki: 0.3 μM) that demonstrates at least 100-fold selectivity over other CYP450 isoforms (Ki: 63/29 μM for CYP2C8/CYP2C18, respectively, and no activity at CYP1A1, CYP1A2, CYP3A4, CYP2C19). At 10 μM, sulfaphenazole has been shown to inhibit endothelium-derived hyperpolarizing factor synthase, a CYP450 isozyme in the porcine coronary artery homologous to CYP2C8/9 that generates reactive oxygen species in coronary endothelial cells and modulates vascular tone and homeostasis.