Synthesis and biological evaluation of nimesulide based new class of triazole derivatives as potential PDE4B inhibitors against cancer cells.

A new class of 1,2,3-triazol derivatives derived from nimesulide was designed as potential inhibitors of PDE4B. Synthesis of these compounds was carried out via a multi-step sequence consisting of copper-catalyzed azide-alkyne cycloaddition (CuAAC) as a key step in aqueous media. The required azide was prepared via the reaction of aryl amine (obtained from nimesulide) with α-chloroacetyl chloride followed by displacing the α-chloro group by an azide. Some of the synthesized compounds showed encouraging PDE4B inhibitory properties in vitro that is >50% inhibition at 30 µM that were supported by the docking studies of these compounds at the active site of PDE4B enzyme (dock scores ~ -28.6 for a representative compound). Two of these PDE4 inhibitors showed promising cytotoxic properties against HCT-15 human colon cancer cells in vitro with IC50 ~ 21-22 µg/mL.