The present invention relates to novel α-keto carbonyl calpain inhibitors for the treatment of neurodegenerative diseases and neuromuscular diseases including Duchenne Muscular Dystrophy, Becker Muscular Dystrophy and other muscular dystrophies. Disuse atrophy and general muscle wasting can also be treated. Generally all conditions where elevated levels of calpains are involved can be treated. The compounds of the invention may also inhibit other thiol proteases such as cathepsin B, cathepsin H, cathepsin L, papain or the like. Multicatalytic Protease (MCP) also known as proteasome may also be inhibited. The compounds of the present invention are also inhibitors of cell damage by oxidative stress through free radicals and can be used to treat mitochondrial disorders and neurodegenerative diseases, where elevated levels of oxidative stress are involved.