The molecule is a tricarboxylic acid anion obtained by deprotonation of the three carboxy groups as well as the 5-hydroxy group of pyrroloquinoline quinol; major microspecies at pH 7.3 (according to Marvin v 6.2.0.). It is a conjugate base of a pyrroloquinoline quinol and a pyrroloquinoline quinol(3-).
2-carboxy-4,5-dioxido-6H-pyrrolo[2,3-f]quinoline-7,9-dicarboxylate