Cell differentiation inducer

A method of treating a malignant tumor selected from the group consisting of leukemia, colorectal cancer, ovarian cancer, oral cancer, lung carcinoma, breast carcinoma, prostate carcinoma and melanoma, which comprises administering to a patient in need thereof, an effective amount of at least one compound represented by formula (1):

• wherein
• A is an optionally substituted phenyl group or an optionally substituted heterocyclic group, wherein the substituent(s) for the phenyl group or the heterocyclic groups is (are) 1 to 4 substituents selected from the group consisting of a halogen atom, a hydroxy group, an amino group, a nitro group a cyano group, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, an aminoalkyl group having 1 to 4 carbons, an alkylamino group having 1 to 4 carbons, an acyl group having 1 to 4 carbons;
• an acylamino group having 1 to 4 carbons, an alkylthio group having 1 to 4 carbons, a perfluoroalkyl group having 1 to 4 carbons, a perfluoroalkyloxy group having 1 to 4 carbons, a carboxyl group, an alkoxycarbonyl group having 1 to 4 carbons, a phenyl group and a heterocyclic group;
• X is a bond or a moiety having a structure selected from those illustrated in formula (2):
• wherein e is an integer of 1 to 4;
• g and m are independently an integer of 0 to 4;
• R4 is a hydrogen atom or an optionally substituted alkyl group having 1 to 4 carbons, or the acyl group represented by formula (3):
• wherein R6 is an optionally substituted alkyl group having 1 to 4 carbons, a perfluoroalkyl group having 1 to 4 carbons, a phenyl group or a heterocyclic group;
• R5 is a hydrogen atom or an optionally substituted alkyl group having 1 to 4 carbons;
• n is an integer of 0 to 4, provided that when X is a bond, n is not zero;
• Q is a moiety having a structure selected from those illustrated in formula (4):
• wherein R7 and R8 are independently a hydrogen atom or an optionally substituted alkyl group have 1 to 4 carbons;
• R1 and R2 are independently a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, an aminoalkyl group having 1 to 4 carbons, an alkylamino group having 1 to 4 carbons, an acyl group having 1 to 4 carbons, an acylamino group having 1 to 4 carbons, an alkylthio group having 1 to 4 carbons, a perfluoroalkyl group having 1 to 4 carbons, a perfluoroalkyloxy group having 1 to 4 carbons, a carboxyl group or an alkoxycarbonyl group having 1 to 4 carbons;
• R3 is a hydroxyl group or an amino group;
• or a pharmaceutically acceptable salt thereof.