2-hexyl-4-Pentynoic acid is a derivative of valproic acid , an inhibitor of histone deacetylases (HDACs). It inhibits HDAC activity more potently (IC50 = 13 μM) than valproic acid (IC50 = 398 μM). 2-hexyl-4-Pentynoic acid induces histone hyperacetylation in cerebellar granule cells significantly at 5 μM. It also induces the expression of heat shock proteins Hsp70-1a and Hsp70-1b and protects cerebellar granule cells from glutamate-induced excitotoxicity when used at a concentration of 50 μM.