First-in-Class Hydrazide-Based HDAC6 Selective Inhibitor with Potent Oral Anti-Inflammatory Activity by Attenuating NLRP3 Inflammasome Activation.

In this study, we report the first highly selective HDAC6 inhibitor with hydrazide as the zinc-binding group (ZBG), which displays superior pharmacokinetic properties to the current hydroxamic acid inhibitors. Structure-activity relationship study reveals that ethyl group substituent hydrazide-based ZBG and cap group with more substantial rigidity and larger volume increase the HDAC6 selectivity of designed compounds. Representative inhibitor exhibits potent HDAC6 inhibitory activity with an IC value of 0.019 μM. To our surprise, establishes significant improvement in the pharmacokinetic property with much higher AUC (10292 ng·h/mL) and oral bioavailability (93.4%) than hydroximic acid-based HDAC6 inhibitors Tubastatin A and ACY-1215. Low-dose remarkably decreases LPS-induced IL-1β release both and by blocking the activation of NLRP3, indicating that can be a potential orally active therapeutic agent for the treatment of NLRP3-related diseases.