2-Hexyl-4-Pentynoic Acid

2-Hexyl-4-Pentynoic Acid is an inhibitor of histone deacetylases (HDACs). It is a derivative of Valproic acid. It inhibits HDAC activity with an IC₅₀ of 13 μM, compared to an IC₅₀ of 398 μM for Valproic acid. It induces histone hyperacetylation at a concentration of 5 μM in cerebellar granule cells and increases HSP70-1a and HSP70-1b mRNA levels at 50 μM. It is neuroprotective against glutamate-induced excitotoxicity.