Patent ID: 7985287

Claim:
An anthrapyridone compound represented by the following formula (1) or a salt thereof: wherein, R 1 represents a hydrogen atom, a lower alkyl group, a hydroxy lower alkyl group, a cyclohexyl group, a mono- or di-lower alkylamino lower alkyl group or a cyano lower alkyl group, R 2 represents a hydrogen atom or a methoxy group, R 3 represents an unsubstituted C5-C12 alkyl group; a substituted C5-C12 alkyl group having, as a substituent, a group selected from the group consisting of an aryl group, a heterocyclic group, a sulfonic acid group, a carboxy group, an alkoxycarbonyl group, an acyl group, a carbamoyl group, a cyano group, an alkoxy group, a phenylalkoxy group, a phenoxy group, a hydroxy group and a nitro group; an unsubstituted aryl group; a substituted aryl group having, as a substituent, a group selected from the group consisting of a halogen atom, a cyano group, a hydroxy group, a sulfonic acid group, a substituted or unsubstituted alkyl group, a carboxy group, an alkoxycarbonyl group, a carbamoyl group, an alkoxy group, a phenoxy group and a nitro group; an unsubstituted heteroaryl group; or a substituted heteroaryl group having, as a substituent, a group selected from the group consisting of a halogen atom, a cyano group, a hydroxy group, a sulfonic acid group, a substituted or unsubstituted alkyl group, a carboxy group, an alkoxycarbonyl group, a carbamoyl group, an alkoxy group, a phenoxy group and a nitro group; respectively, and with regard to the substitution positions of —SO 2 R 3 and —SO 3 H whose substitution position are not specified and the both of which the benzene ring has thereon, one of their substitution positions is the para-position and the other thereof is the ortho-position to the substitution position of the nitrogen atom by which said benzene ring is substituted.