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 compound of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are, independently, a hydrogen atom, a monosaccharide residue, a protected monosaccharide residue, or a protecting group for hydroxyl group, but at least one of R.sup.1 and R.sup.2 is a monosaccharide residue or a protected monosaccharide residue, and R.sup.3 is a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, or an aralkyl group, with the proviso that (1) when R.sup.1 and R.sup.2 are glucose residues at the same time, R.sup.3 is not a hydrogen atom, (2) when R.sup.1 is a hydrogen atom, an acetyl group or a benzyl group and R.sup.2 is a glucose residue, an acetylated glucose residue, or acetalized glucose residue, R.sup.3 is not a hydrogen atom, or (3) when R.sup.1 is a glucose residue and R.sup.2 is a hydrogen atom, R.sup.3 is not a hydrogen atom or a salt thereof is disclosed.

Abstract: A compound of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are, independently, --CON(R.sup.4)R.sup.5, or a monosaccharide, or acylated monosaccharide group, with the proviso that at least one of R.sup.1 and R.sup.2 is --CON(R.sup.4)R.sup.5, and R.sup.4 and R.sup.5 are, independently, a hydrogen atom, or a hydroxyl, alkyl, aryl, or aralkyl group, or R.sup.4 and R.sup.5 together with the nitrogen atom attached thereto form a 3- to 7-membered saturated cycloaliphatic amino group, and R.sup.3 is a hydrogen atom, or a hydroxyl, alkyl, aryl, aralkyl, or --COOR.sup.8 group, and R.sup.3 is at 3- or 4-position, and R.sup.8 is a hydrogen atom or an alkyl group, or a salt thereof is disclosed. The compound has a function to inhibit a matrix metalloproteinase.

Abstract: A chromone derivative of the formula (I): ##STR1## wherein R.sup.11 is a pyrazolyl, pyrrolyl, triazolyl, benzotriazolyl, benzimidazolyl, indazolyl, or indolyl group, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 is independently a hydrogen or halogen atom, or a hydroxy or alkoxy group, or an alkoxy group substituted with one or more alkoxy groups, and X is an oxygen or sulfur atom, or a salt thereof is disclosed. The chromone derivative inhibits the activity of matrix metalloproteinase.

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: The present invention discloses a method for treating a patient suffering from osteoarthritis comprising administering a physiologically effective amount of pharmaceutical composition containing at least one compound, as an active ingredient, represented by the formula (I): ##STR1## wherein R represents a hydrogen atom or an acyl group; X represents a CHO group, a COOH group, a physiologically acceptable salt thereof or a CH(OR').sub.2 group wherein R' represents an acyl group.