Patent ID: 8853175

Claim:
A pharmaceutical composition comprising a compound of formula (I): or a pharmaceutically acceptable salt, solvate, or stereoisomer thereof, wherein: R 1 is hydrogen or —C(O)R 5 ; R 2 is hydrogen, methyl, or glucuronide (gluc); R 3 is hydrogen, ethyl, or gluc; R 4 is hydrogen or hydroxyl; R 5 is straight chain alkyl containing 1 to 6 carbon atoms, optionally substituted with —OR 6 ; and R 6 is hydrogen or gluc; when R 1 is —C(O)R 5 and R 5 is unsubstituted methyl: R 2 is hydrogen and R 3 is ethyl; R 2 is hydrogen and R 3 is hydrogen; R 2 is gluc and R 3 is ethyl; R 2 is methyl and R 3 is gluc; or R 2 is methyl and R 3 is hydrogen; with the proviso that when R 2 is methyl, R 3 is ethyl and R 4 is hydrogen, then R 1 cannot be hydrogen.