Design and synthesis of a novel class of carbonic anhydrase-IX inhibitor 1-(3-(phenyl/4-fluorophenyl)-7-imino-3H-[1,2,3]triazolo[4,5d]pyrimidin 6(7H)yl)urea

•Pyrimidine urea derived compound TPUI binds to CAIX with high affinity and selectivity.•TPUI is preferentially docked in the active site cavity of CAIX.•Fluorescence binding study is consistent with docking and MD simulation studies.•TPUI appeared as novel class of CAIX inhibitor against hypoxia-induced cancer.

Carbonic anhydrase IX (CAIX) is a promising target in cancer therapy especially in the case of hypoxia-induced tumors. The selective inhibition of CA isozymes is a challenging task in drug design and discovery process. Here, we performed fluorescence-binding studies and inhibition assay combined with molecular docking and molecular dynamics (MD) simulation analyses to determine the binding affinity of two synthesized triazolo-pyrimidine urea derived (TPUI and TPUII) compounds with CAIX and CAII. Fluorescence binding results are showing that molecule TPUI has an excellent binding-affinity for CAIX (kD = 0.048 μM). The TPUII also exhibits an appreciable binding affinity (kD = 7.52 μM) for CAIX. TPUI selectively inhibits CAIX as compared to TPUII in the 4-NPA assay. Docking studies show that TPUI is spatially well-fitted in the active site cavity of CAIX, and is involve in H-bond interactions with His94, His96, His119, Thr199 and Thr200. MD simulation studies revealed that TPUI efficiently binds to CAIX and essential active site residual interaction is consistent during the entire simulation of 40 ns. These studies suggest that TPUI appeared as novel class of CAIX inhibitor, and may be used as a lead molecule for the development of potent and selective CAIX inhibitor for the hypoxia-induced cancer therapy.

Graphical abstractCartoon view of TPUI docked with CAIX.Figure optionsDownload full-size imageDownload high-quality image (135 K)Download as PowerPoint slide