SMILES: C1=C(C=C(OC1O)C(=O)[O-])C(=O)[O-]
Description: The molecule is a dicarboxylic acid dianion arising from deprotonation of both carboxy groups of 4-carboxy-2-hydroxymuconate semialdehyde hemiacetal; major species at pH 7.3. It is a conjugate base of a 4-carboxy-2-hydroxymuconate semialdehyde hemiacetal.