SMILES: C1=CC(=CC=C1N=NC2=CC(=C(C=C2)N=NC3=C4C=CC(=CC4=CC(=C3O)S(=O)(=O)O)S(=O)(=O)O)S(=O)(=O)O)S(=O)(=O)O
Description: The molecule is an arenesulfonic acid that is 3-hydroxynaphthalene-2,7-disulfonic acid carrying a {2-sulfo-4-[(4-sulfophenyl)diazenyl]phenyl}diazenyl group at position 4. The tetrasodium salt is the biological stain 'Ponceau S'. It has a role as a histological dye and a fluorochrome. It is an arenesulfonic acid, a member of azobenzenes, a bis(azo) compound and a member of naphthols. It is a conjugate acid of a Ponceau S(4-).