Structure‐based discovery of new selective small‐molecule sirtuin 5 inhibitors

Human sirtuin 5 ( SIRT 5) is a protein deacylase regulating metabolic pathways and stress responses and is implicated in metabolism‐related diseases. Small‐molecule inhibitors for SIRT 5 are sought as chemical tools and potential therapeutics. Herein, we proposed a customized virtual screening approach targeting catalytically important and unique residues Tyr102 and Arg105 of SIRT 5. Of the 20 tested virtual screening hits, six compounds displayed marked inhibitory activities against SIRT 5. For the hit compound 19 , a series of newly synthesized ( E )‐2‐cyano‐N‐phenyl‐3‐(5‐phenylfuran‐2‐yl)acrylamide derivatives/analogues were carried out structure–activity relationship analyses, resulting in new more potent inhibitors, among which 37 displayed the most potent inhibition to SIRT 5 with an IC 50 value of 5.59 ± 0.75 μM. The biochemical studies revealed that 37 likely acts via competitive inhibition with the succinyl‐lysine substrate, rather than the NAD + cofactor, and it manifested substantial selectivity for SIRT 5 over SIRT 2 and SIRT 6. This study will aid further efforts to develop new selective SIRT 5 inhibitors as tools and therapeutics.