Abstract: A chondroprotective agent comprising a flavonoid compound of the general formula (I): wherein R1 to R9 are, independently, a hydrogen atom, hydroxyl group, or methoxyl group and X is a single bond or a double bond, or a stereoisomer thereof, or a naturally occurring glycoside thereof is disclosed. The above compound strongly inhibits proteoglycan depletion from the chondrocyte matrix and exhibits a function to protect cartilage, and thus, is extremely effective for the treatment of arthropathy.

Abstract: A chondroprotective agent comprising a flavonoid compound of the general formula (I): ##STR1## wherein R.sup.1 to R.sup.9 are, independently, a hydrogen atom, hydroxyl group, or methoxyl group and X is a single bond or a double bond, or a stereoisomer thereof, or a naturally occurring glycoside thereof is disclosed. The above compound strongly inhibits proteoglycan depletion from the chondrocyte matrix and exhibits a function to protect cartilage, and thus, is extremely effective for the treatment of arthropathy.

Abstract: A chondroprotective agent comprising a carboxylic acid compound of the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are, independently, a hydrogen atom or an alkyl group of 1 to 6 carbon atoms, or a cis- or trans-isomer thereof, or a pharmaceutically acceptable salt or ester thereof, and a pharmaceutically acceptable carrier is disclosed. The above compound strongly inhibits proteoglycan depletion from the chondrocyte matrix and exhibits a function to protect cartilage, and thus, is extremely effective for the treatment of arthropathy.

Abstract: A pharmaceutical composition comprising a compound of the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are, independently, a hydrogen atom, a saturated or unsaturated aliphatic acyl having 2 to 25 carbon atoms or benzoyl group and R.sup.3 is a hydrogen atom or alkyl group, and a pharmaceutically acceptable carrier is disclosed. Further, a novel compound of the general formula (I) wherein R.sup.1 and R.sup.2 are, independently, a hydrogen atom, pivaloyl, capryloyl, lauroyl, palmitoyl, stearoyl, linoleoyl, docosahexaenoyl, or benzoyl group, and R.sup.3 is a hydrogen atom or methyl group, is also disclosed.

Abstract: Disclosed herein are a derivative of dihydroxybenzamide represented by the formula(I): ##STR1## wherein (1) R.sup.1 represents a hydrogen atom or a lower alkyl group and R.sup.2 represents a straight chain-alkyl group of 4 to 12 carbon atoms, a branched chain-alkyl group of 4 to 12 carbon atoms, a cyclo-alkyl group of 4 to 12 carbon atoms, ##STR2## wherein n is an integer of 1 to 6, or a pyridyl group which is substituted or unsubstituted, or (2) R.sup.1 and R.sup.2 are cyclized to make a heterocycle containing amino group represented by the formula ##STR3## wherein X represents a nitrogen atom or a methine and Y represents a hydrogen atom, an alkyl group of 1 to 6 carbon atoms or a phenyl group, and a pharmaceutical composition containing the same.

Abstract: Disclosed herein are a derivative of dihydroxybenzamide represented by the formula(I): ##STR1## wherein (1) R.sup.1 represents a hydrogen atom or a lower alkyl group and R.sup.2 represents a straight chain-alkyl group of 4 to 12 carbon atoms, a branched chain-alkyl group of 4 to 12 carbon atoms, a cyclo-alkyl group of 4 to 12 carbon atoms, ##STR2## wherein n is an integer of 1 to 6, or a pyridyl group which is substituted or unsubstituted, or (2) R.sup.1 and R.sup.2 are cyclized to make a heterocycle containing amino group represented by the formula ##STR3## wherein X represents a nitrogen atom or a methine and Y represents a hydrogen atom, an alkyl group of 1 to 6 carbon atoms or a phenyl group, and a pharmaceutical composition containing the same.