Patent ID: 7018993

Claim:
A compound of general formula (I): wherein X 1 is hydrogen, and X 2 is a group of general formula (II): -Ar-A-G-E (II) having an α-configutation, R a represents a hydrogen atom or a protecting group for a hydroxyl group, R b and R c form an optionally protected —(C═O)— together with the 3-position carbon atom attached to R b and R c , and the broken line forms a single bond or a double bond together with the solid line, wherein Ar is a single bond or an aromatic hydrocarbon group, A is a methylene group wherein Ar is a single bond, and A is —O— when Ar is an aromatic hydrocarbon group, G is an optionally hydroxyl substituted linear C 2 –C 15 alkylene group, and E represents a group selected from the following formulae E 1 to E 10 : wherein R 1 and R 2 , which are the same or different, each represent a group of general formula (III): -J-G 2 -Q-Z (III) [wherein J represents a single bond, a methylene group or —O—, G 2 represents a single bond, an optionally substituted linear or branched C 1 –C 10 alkylene group, an optionally substituted linear or branched C 2 –C 10 alkenylene group, or an optionally substituted linear or branched C 2 –C 10 alkynylene group, Q represents a single bond or a group selected from the following formulae Q 1 to Q 10 : (wherein R 3 and R 4 , which are the same or different, each represent a hydrogen atom or a linear or branched C 1 –C 10 lower alkyl group, the bond marked with * is linked to G 2 , and the bond marked with ** is linked to Z), and Z represents a hydrogen atom, a linear or branched C 1 –C 10 alkyl group which may be substituted with a halogen atom, a linear or branched C 2 –C 10 alkenyl group which may be substituted with a halogen atom, a linear or branched C 2 –C 10 alkynyl group which may be substituted with a halogen atom, or a group of general formula (IV): —O—R d (IV) (wherein R d represents a hydrogen atom or a protecting group for a hydroxyl group)], provided Z is not a hydrogen atom when J, G 2 and Q simultaneously represent a single bond, or a pharmaceutically acceptable salt of the compound or a prodrug thereof.