Xanthenedione derivatives for the treatment of pigmentation and skin ageing disorders

Disclosed is the use of a 9-(4-hydroxy-3-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6-tetrahydro-9H-xanthene-1,8(2H,7H)-dione and its analogues as represented by general formula (I'), or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, in the manufacture of a medicament for treating and/or preventing the inflammation of the skin, wherein the medicament is formulated for topical administration; wherein: R1 and R2 represent simultaneously or independently: OH, hydrogen, alkyl, alkoxy, halogen, or OCOR3; R4 represents: hydrogen, or an acetylated radical COR5, or a pyranose radical which may be partially or totally acetylated; R6 and R7 represent: simultaneously hydrogen or methyl, or when R6 represents hydrogen, R7 represents an alkyl radical or an optionally substituted phenyl, or R6 and R7 are bonded to each other and form a cycloalkyl ring; and wherein the remaining substituents are as defined herein. Representative compounds of formula (I) include 9-(4-hydroxy-3-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6-tetrahydro-9H-xanthene-1,8(2H,7H)-dione, 2-methoxy-4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl palmitate, (9Z,12Z)-2-methoxy-4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl octadeca-9,12-dienoate, (3R,4S,5S)-2-(acetoxymethyl)-6-(2-methoxy-4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenoxy)tetrahydro-2H-pyran-3,4,5-triyl triacetate, 9-(3-methoxy-4-((3S,4S,5S)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yloxy)phenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, (3S,4S,5S,6S)-2-(acetoxymethyl)-6-(2-methoxy-4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenoxy)tetrahydro-2H-pyran-3,4,5-triyl triacetate, 9-(3-methoxy-4-((2S,3S,4S,5R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yloxy)phenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, (3R,4S,5S,6S)-2-(acetoxymethyl)-6-(4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenoxy)tetrahydro-2H-pyran-3,4,5-triyl triacetate and 3,3,6,6-tetramethyl-9-(4-((2S,3S,4S,5S)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yloxy)phenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione.