Abstract: A compound represented by the formula: ##STR1## wherein X represents a sulfur atom or an oxygen atom; Y represents an optionally oxidized sulfur atom or an oxygen atom; Z represents a bond or a divalent hydrocarbon group; R.sup.1 represents an optionally substituted hydrocarbon group; R.sup.2 represents an optionally amidated or esterified carboxyl group; ring A represents an optionally substituted aromatic 5-membered heterocyclic ring; or a salt thereof. A compound of the above formula possesses cell differentiation inducing factor action-enhancing activity and anti-matrix metalloprotease activity and that is useful in the prevention and treatment of bone diseases such as osteoporosis, bone fractures, osteoarthritis and rheumatoid arthritis, arteriosclerosis, cancer metastasis, and diseases based on nerve degeneration.

Abstract: The present invention provides a cathepsin L inhibitor containing a compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or an arylalkyl, heterocyclic-alkyl or lower alkyl group which may be substituted; R.sup.2 and R.sup.3 independently are a hydrogen atom or a hydrocarbon residue which may be substituted; R.sup.4 is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group which may be substituted; X is formula: --CHO or --CH.sub.2 OB (wherein B is a hydrogen atom or a protecting group of hydroxyl group); m and n independently are an integer of 0 or 1; provided that R.sup.4 is an alkanoyl group substituted by aryl, a sulfonyl group substituted by aryl having more than 9 carbon atoms or by lower alkyl, or a carbamoyl or thiocarbamoyl group which may be substituted when R.sup.1 is an unsubstituted lower alkyl, arylalkyl on methylthioethyl group, R.sup.2 and R.sup.3 independently are a lower alkyl or arylalkyl, X is --CHO, m is 1 and n is 0 or 1, or a salt thereof.

Abstract: The present invention provides a cathepsin L inhibitor containing a compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or an arylalkyl, heterocyclic-alkyl or lower alkyl group which may be substituted; R.sup.2 and R.sup.3 independently are a hydrogen atom or a hydrocarbon residue which may be substituted; R.sup.4 is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group which may be substituted; X is formula: --CHO or --CH.sub.2 OB (wherein B is a hydrogen atom or a protecting group of hydroxyl group); m and n independently are an integer of 0 or 1; provided that R.sup.4 is an alkanoyl group substituted by aryl, a sulfonyl group substituted by aryl having more than 9 carbon atoms or by lower alkyl, or a carbamoyl or thiocarbamoyl group which may be substituted when R.sup.1 is an unsubstituted lower alkyl, arylalkyl on methylthioethyl group, R.sup.2 and R.sup.3 independently are a lower alkyl or arylalkyl, X is --CHO, m is 1 and n is 0 or 1, or a salt thereof.

Abstract: The present invention provides a cathepsin L inhibitor containing a compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or an arylalkyl, heterocyclic-alkyl or lower alkyl group which may be substituted; R.sup.2 and R.sup.3 independently are a hydrogen atom or a hydrocarbon residue which may be substituted; R.sup.4 is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group which may be substituted; X is formula: --CHO or --CH.sub.2 OB (wherein B is a hydrogen atom or a protecting group of hydroxyl group); m and n independently are an integer of 0 or 1; provided that R.sup.4 is an alkanoyl group substituted by aryl, a sulfonyl group substituted by aryl having more than 9 carbon atoms or by lower alkyl, or a carbamoyl or thiocarbamoyl group which may be substituted when R.sup.1 is an unsubstituted lower alkyl, arylalkyl on methylthioethyl group, R.sup.2 and R.sup.3 independently are a lower alkyl or arylalkyl, X is --CHO, m is 1 and n is 0 or 1, or a salt thereof.

Abstract: The present invention provides a cathepsin L inhibitor containing a compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or an arylalkyl, heterocyclic-alkyl or lower alkyl group which may be substituted; R.sup.2 and R.sup.3 independently are a hydrogen atom or a hydrocarbon residue which may be substituted; R.sup.4 is an alkanoyl, sulfonyl, carbonyloxy, carbamoyl or thiocarbamoyl group which may be substituted; X is formula: --CHO or --CH.sub.2 OB (wherein B is a hydrogen atom or a protecting group of hydroxyl group); m and n independently are an integer of 0 or 1; provided that R.sup.4 is an alkanoyl group substituted by aryl, a sulfonyl group substituted by aryl having more than 9 carbon atoms or by lower alkyl, or a carbamoyl or thiocarbamoyl group which may be substituted when R.sup.1 is an unsubstituted lower alkyl, arylalkyl on methylthioethyl group, R.sup.2 and R.sup.3 independently are a lower alkyl or arylalkyl, X is --CHO, m is 1 and n is 0 or 1, or a salt thereof.