A novel series of urea-based peptidomimetic calpain inhibitors

A series of peptide aldehyde derivatives in which the P2 chiral carbon has been replaced with nitrogen were synthesized as urea-based peptidomimetic inhibitors of μ-calpain. The compounds mirrored the general SAR of peptidyl aldehyde calpain inhibitors but displayed greater selectivity for μ-calpain over cathepsin B.