Pifithrin-β is a potent p53 inhibitor with an IC₅₀ of 23 μM.

IC50: 23 μM (p53)^[1]

Pifithrin-α, an inhibitor of the p53 protein, is regarded as a lead compound for cancer and neurodegenerative disease therapy. Pifithrin-α is very unstable in culture medium and rapidly converts to its condensation product pifithrin-β, the N-acetyl derivative^[2]. After 24 h, the viability assay shows that the pretreatments with 1 and 10 μM pifithrin-β exerts neuroprotective effects^[3].

• [1]. Christodoulou MS, et al. Synthesis and biological evaluation of imidazolo[2,1-b]benzothiazole derivatives, as potential p53 inhibitors. Bioorg Med Chem. 2011 Mar 1;19(5):1649-57.

  [2]. Fernández-Cruz ML, et al. Biological and chemical studies on aryl hydrocarbon receptor induction by the p53 inhibitor pifithrin-α and its condensation productpifithrin-β. Life Sci. 2011 Apr 25;88(17-18):774-83.

  [3]. Da Pozzo E, et al. p53 functional inhibitors behaving like pifithrin-β counteract the Alzheimer peptide non-β-amyloid component effects in human SH-SY5Y cells. ACS Chem Neurosci. 2014 May 21;5(5):390-9.