Calpain inhibitor (IC50 = 0.09 μM) that activates p53-dependent apoptosis in tumor cell lines. Increases activated p53, p21 and caspase levels and promotes cell cycle arrest through inhibition of cyclin D degradation in vitro. Also attenuates ischemia/reperfusion injury in cardiomyocytes, hepatocytes and renal tubular cells through downregulation of iNOS and COX-2 expression. MW (observed): 383.53.