Patent ID: 6881727

Claim:
A composition for inhibiting metalloproteinase which comprises a compound of the formula I: wherein R 1 is optionally substituted lower alkyl, optionally substituted aryl, optionally substituted aralkyl or optionally substituted heteroaryl; R 2 is a hydrogen atom, optionally substituted lower alkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroarylalkyl; R 3 is optionally substituted arylene; R 4 is —CH═CH—, —C≡C—, —SO 2 —NH—N═CH—, or tetrazol-diyl; R 5 is optionally substituted aryl; and Y is —NHOH or —OH; provided R 2 is a hydrogen atom when Y is —NHOH; or an optically active substance, a pharmaceutically acceptable salt, or hydrate thereof.