1-Naphthohydroxamic acid (E6577-GRP)

1-Naphthohydroxamic acid (Compound 2) demonstrates potent and selective inhibition of HDAC8 (IC50 = 14 μM), exhibiting significantly greater selectivity for HDAC8 compared to class I HDAC1 and class II HDAC6 (IC50 >100 μM). This compound does not elevate global histone H4 acetylation levels nor decrease total intracellular HDAC activity. Additionally, 1-naphthohydroxamic acid has been shown to promote tubulin acetylation.