SMILES: COC1=CC=CC(=C1)N=NC2=C(C=C3C=C(C=CC3=C2O)NC(=O)NC4=CC5=CC(=C(C(=C5C=C4)O)N=NC6=CC7=C(C=C6)C=C(C=C7)S(=O)(=O)O)S(=O)(=O)O)S(=O)(=O)O
Description: The molecule is a naphthalenesulfonic acid that is the free acid form of the dye benzo scarlet 4BNS. The trisodium salt is a direct cotton dye that is also capable of hydrogen bonding to amyloid and giving a dark enough red colour to be useful in diagnostic histology. It is a naphthalenesulfonic acid, a member of naphthols, a bis(azo) compound, a member of azobenzenes, a member of ureas and an aromatic ether. It is a conjugate acid of a benzo scarlet 4BNS(3-).