Pifithrin-β hydrobromide (Cyclic PFT-α) is an inhibitor of p53; reversibly blocks p53-dependent transcriptional activation and apoptosis. Protects against neuronal death in models of stroke and neurodegenerative disorders. Active in vivo; protects mice from the side-effects of Y therapy associated with p53 induction. Supresses self-renewal of embryonic stem cells. Also aryl hydrocarbon receptor (AHR) agonist, causes upregulation of AHR target gene CYP1A1 (EC50 = 1.1 μM).

p53:23 μM(EC50)

PFTα分子不能取得激活AhR所需的平面构形，而Pifithrin-β hydrobromide则显示出与典型AhR配体β-萘酚相似的构形。在两种细胞系中，PFTα和Pifithrin-β hydrobromide引发了与AhR激活相关的不同反应。然而，当通过乙酰化外环氮阻碍PFTα向Pifithrin-β hydrobromide的环化时，所有这些反应均未观察到。这些结果导致一个结论，即AhR的激活很可能是由Pifithrin-β hydrobromide而非PFTα引起的。