Lactol derivatives as inhibiters of cathepsin L.

摘要

The present invention provides novel compound of the formulas (Ia) or (I): wherein Q is one or two amino acid residues which may be substituted; R<3> is a carboxyl group which may be esterified or an acyl group; A is an alkylene group; B is hydrogen or an alkyl group which may be substituted or an acyl group; or a salt thereof; wherein R<1> and R<2> may be the same or different and each is hydrogen or a hydrocarbon residue which may be substituted; R<3>, A and B have the same definitions as those shown above; m and n each is 0 or 1; provided that where both m and n are both equal to 0, R<3> is a carboxyl group which may be esterified or an acyl group having not less than 7 carbon atoms; or a salt thereof. The compound (Ia) or (I) shows cathepsin L inhibitory and bone resorption inhibitory activities and are useful as a prophylactic/therapeutic agent for osteoporosis.