Prostaglandin derivative

A compound, represented by formula (1) or a pharmaceutically acceptable salt thereof;

• wherein
• RA is —CH2—CZ1Z2(COX) or —CH═CZ1(COX),
• Z1 and Z2 are each independently a hydrogen atom or a fluorine atom,
• X is OR4 or NR5R6,
• R4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a substituted alkyl group having 1 to 6 carbon atoms,
• R5 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a substituted alkyl group having 1 to 6 carbon atoms,
• R6 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a substituted alkyl group having 1 to 6 carbon atoms, an alkylsulfonyl group having 1 to 6 carbon atoms, a substituted alkylsulfonyl group having 1 to 6 carbon atoms, an arylsulfonyl group having 6 to 10 carbon atoms or a substituted arylsulfonyl group having 6 to 10 carbon atoms;
• Y is CH2, S or O;
• A-B is a carbon-carbon single bond or a carbon-carbon double bond;
• a hydroxy group bonded by a wavy line is a hydroxy group having α-configuration, β-configuration or a mixed configuration of α-configuration and β-configuration;
• R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a substituted alkyl group having 1 to 3 carbon atoms;
• n is an integer of 0 to 2;
• and
• R3 is an alkyl group having 2 to 3 carbon atoms or a cycloalkyl group having 3 to 5 carbon atoms.