label: 4,4'-(carbonylbis(imino-3-benzoylimino))-bis(5-hydroxynaphthalene-2,7-disulfonic acid) tetrapotassium salt
label_lc: 4,4'-(carbonylbis(imino-3-benzoylimino))-bis(5-hydroxynaphthalene-2,7-disulfonic acid) tetrapotassium salt