SMILES: C1=CC(=C(C(=C1C(=O)O)C(=O)O)[O-])[O-]
Description: The molecule is dicarboxylate anion of 3,4-dihydroxyphthalic acid; major species at pH 7.3. It derives from a phthalate(2-). It is a conjugate base of a 3,4-dihydroxyphthalic acid.