AMINOBUTANOIC ACID DERIVATIVES

An aminobutyric acid derivative of the formula (I): (wherein all symbols are as defined in the specification) and salt thereof. salt thereof. The compounds of the formula (I) possess an inhibitory activity on matrix metalloproteinase and are useful for prevention and / or treatment of diseases, for example, rheumatoid diseases, arthrosteitis, unusual bone resorption, osteoporosis, periodontitis, interstitial nephritis, arteriosclerosis, pulmonary emphysema, cirrhosis, cornea injury, metastasis of, invasion of or growth of tumor cells, autoimmune disease (e.g. Crohn's disease, Sjogren's syndrome), disease caused by vascular emigration or infiltration of leukocytes, arterialization, multiple sclerosis, aorta aneurysm, endometriosis.