The molecule is a dicarboxylic acid dianion obtained by deprotonation of the carboxy groups of 2-hydroxyhepta-2,4-diene-1,7-dioic acid; major species at pH 7.3. It is a conjugate base of a (2Z,4Z)-2-hydroxyhepta-2,4-dienedioic acid. It is a tautomer of a (4Z)-2-oxohept-4-enedioate.
(3Z,5Z)-7-hydroxy-6-oxido-7-oxohepta-3,5-dienoate