SMILES: C1=CC=C(C=C1)N2C3=CC=CC=C3N=C4C2=CC(=NC5=C(C=C(C=C5)S(=O)(=O)O)S(=O)(=O)O)C6=C4C=CC(=C6)S(=O)(=O)O
Description: The molecule is an organic heterotetracyclic compound that is 7-phenyl-5-imino-5,7-dihydrobenzo[a]phenazine-3-sulfonic acid in which the imino hydrogen is replaced by a 2,4-disulfophenyl group. The disodium salt is the biological stain 'azocarmine B'. It is an arenesulfonic acid, an imine and an organic heterotetracyclic compound. It is a conjugate acid of an azocarmine B(2-).