Summary
Novelty: Novel calpain inhibitors, including ketopeptides, halopeptides and isocoumarins are disclosed. They are said to be useful in the treatment of neurodegenerative diseases due to their effect on intracellular free calcium. Examples of use include stroke, Alzheimer's disease, head trauma and HIV-induced neuropathy.
Biology: Comprehensive data are presented, including Ki values for the inhibition of cysteine proteases (papain, (P); calpain I, (CI); cathepsin B, (CB); and calpain II, (CII)). Two peptide examples are Z-Leu-Phe COOEt (Ki CI = 0.23 and CII = 0.4 μM) and Z-Leu-Abu-COOEt (Ki CI = 0.04 and CII = 0.4 μM). An example of the isocoumarins is 7-amino-4-chloro-3-(3-isothiureidopropoxy)isocoumarin (IC50 CI = 10 μM). A figure is given showing inhibition of glutamate-induced cell death by a number of calpain inhibitors.
Chemistry: A very large number of ketopeptides and isocoumarins are exemplified. The peptides are prepared using standard techniques.
Structure: