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. Compound (I) is useful as a prophylactic/therapeutic agent for osteoporosis.
本发明提供了一种含有式为:##STR1##的化合物的半胱
氨酸
蛋白酶L
抑制剂,其中R.sup.1为氢原子或取代的芳基烷基,杂环基烷基或低级烷基;R.sup.2和R.sup.3独立地为氢原子或可取代的碳氢残基;R.sup.4为可取代的烷酰基,磺酰基,羰氧基,
氨基甲酰基或
硫脲甲酰基;X为公式:--CHO或--CH.sub.2 OB(其中B为氢原子或羟基保护基);m和n独立地为0或1的整数;前提是当R.sup.1为未取代的低级烷基,芳基烷基或甲基
硫乙基时,R.sup.4为取代的烷酰基,芳基取代的磺酰基具有9个以上的碳原子或低级烷基,或可取代的
氨基甲酰基或
硫脲甲酰基,R.sup.2和R.sup.3独立地为低级烷基或芳基烷基,X为--CHO,m为1,n为0或1,或其盐。化合物(I)可用作骨质疏松症的预防/治疗药物。