ChEBI: Valproic acid is a branched-chain saturated fatty acid that comprises of a propyl substituent on a pentanoic acid stem. It has a role as an anticonvulsant, a GABA agent, an EC 3.5.1.98 (histone deacetylase) inhibitor, a teratogenic agent, a psychotropic drug, a neuroprotective agent and an antimanic drug. It is a branched-chain saturated fatty acid and a branched-chain fatty acid. It derives from a valeric acid. It is a conjugate acid of a valproate.NCI Thesaurus (NCIt): Valproic Acid is a synthetic derivative of propylpentanoic acid with antiepileptic properties and potential antineoplastic and antiangiogenesis activities. In epilepsy, valproic acid appears to act by increasing the concentration of gamma-aminobutyric acid (GABA) in the brain. This agent's antitumor and antiangiogenesis activities may be related to the inhibition of histone deacetylases and nitric oxide synthase, which results in the inhibition of nitric oxide synthesis. (NCI04)