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; R³ 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 R¹ and R² may be the same or different and each is hydrogen or a hydrocarbon residue which may be substituted; R³, 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, R³ 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.
The present invention provides novel compound of the formulas (Ia) or (I): ##STR1## wherein Q is one or two amino acid residues which may be substituted; R.sup.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; ##STR2## wherein R.sup.1 and R.sup.2 may be the same or different and each is hydrogen or a hydrocarbon residue which may be substituted; R.sup.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.sup.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.