MMPSI is a potent and selective small molecule caspase 3 and caspase 7 inhibitor with an IC50 of 1.7 μM for human caspase-3. MMPSI can significantly reduce ischemia-reperfusion-induced infarct size in the isolated rabbit heart, and reduce apoptosis in both the ischemic myocardium and isolated cardiomyocytes. MMPSI can be used for researching cardioprotection[1].