carboxylic acid anion fumarate(1-) -1 115.00368 115.064 gmelin:325290 (2E)-3-carboxyacrylate InChI=1S/C4H4O4/c5-3(6)1-2-4(7)8/h1-2H,(H,5,6)(H,7,8)/p-1/b2-1+ hydrogen fumarate VZCYOOQTPOCHFL-OWOJBTEDSA-M chebi_ontology C4H3O4 A hydrogen butenedioate obtained by deprotonation of one of the carboxy groups of fumaric acid. fumarate monoanion CHEBI:37154 (2E)-3-carboxyprop-2-enoate reaxys:1906438 (2E)-3-carboxyprop-2-enoate O=C([O-])/C=C/C(=O)O