Fragment-based discovery of novel and selective mPGES-1 inhibitors Part 1: Identification of sulfonamido-1,2,3-triazole-4,5-dicarboxylic acid

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible prostaglandin E synthase that catalyzes the conversion of prostaglandin PGH2 to PGE2 and represents a novel target for therapeutic treatment of inflammatory disorders. It is essential to identify mPGES-1 inhibitor with novel scaffold as new hit or lead compound for the purpose of the next-generation anti-inflammatory drugs. Herein we report the discovery of sulfonamido-1,2,3-triazole-4,5-dicarboxylic derivatives as a novel class of mPGES-1 inhibitors identified through fragment-based virtual screening and in vitro assays on the inhibitory activity of the actual compounds. 1-[2-(N-Phenylbenzenesulfonamido)ethyl]-1H-1,2,3-triazole-4,5-dicarboxylic acid (6f) inhibits human mPGES-1 (IC50 of 1.1 μM) with high selectivity (ca.1000-fold) over both COX-1 and COX-2 in a cell-free assay. In addition, the activity of compound 6f was again tested at 10 μM concentration in presence of 0.1% Triton X-100 and found to be reduced to 1/4 of its original activity without this detergent. Compared to the complete loss of activity of nuisance inhibitor with the detergent, therefore, compound 6f would be regarded as a partial nuisance inhibitor of mPGES-1 with a novel scaffold for the optimal design of more potent mPGES-1 inhibitors.