3-[[1-hydroxy-6-[[[[4-[(8-hydroxy-3,6-disulpho-1-naphthyl)azo]-2-methoxy-5-methylphenyl]amino]carbonyl]amino]-3-sulpho-2-naphthyl]azo]-p-anisic acid

3-[[1-Hydroxy-6-[[[[4-[(8-hydroxy-3,6-disulfo-1-naphtyl)azo]-2-methoxy-5-methylphenyl]amino]carbonyl]amino]-3-sulfo-2-naphtyl]azo]-4-methoxybenzoic acid