SMILES: C1=CC2=C(C=C1S(=O)(=O)O)C(=C(C=C2[N+](=O)[O-])[N+](=O)[O-])O
Description: The molecule is a naphthalenesulfonic acid that is naphthalene-2-sulfonic acid substituted by nitro groups at positions 5 and 7 as well as a hydroxy group at position 8. The disodium salt is the biological stain 'naphthol yellow S'. It has a role as a histological dye. It is a member of naphthols, a naphthalenesulfonic acid and a C-nitro compound. It is a conjugate acid of a flavianate.