The molecule is an organosulfonate oxoanion obtained by deprotonation of the sulfo groups of 7-phenyl-5-[(4-sulfophenyl)imino]-5,7-dihydrobenzo[a]phenazine-3-sulfonic acid. It is a conjugate base of an azocarmine G free acid.
7-phenyl-5-(4-sulfonatoanilino)benzo[a]phenazin-7-ium-3-sulfonate