Structure-activity relationship and interaction studies of new SIRT1 inhibitors with the scaffold of 3-(furan-2-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole.

Abstract SIRT1 is a NAD + -dependent deacetylase. It deacetylates a broad range of substrates and is involved in multiple diseases such as type 2 diabetes and cancer. Here we discovered a new class of SIRT1 inhibitors with the scaffold of 3-(furan-2-yl)-[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazole. The inhibitors up-regulate acetyl p53 level in human breast cells MCF-7. The docking simulations indicated that the scaffold and the R-substituents of the inhibitors bind in the C and D pocket of SIRT1, respectively, which was supported by the structure–activity relationship and SIRT1 mutagenesis studies. We propose that binding of the inhibitors repels the entering of the nicotinamide moiety of NAD + to the C pocket, prevents its transformation to the productive conformation and therefore inhibits the deacetylation catalyzed by SIRT1.