Discovery of highly potent DENV NS2B-NS3 covalent inhibitors containing a phenoxymethylphenyl residue.

Dengue virus (DENV) has developed rapidly in the past few decades and has been becoming the most widespread arbovirus in the world. The vital role of NS2B-NS3 in virus replication and maturation of relevant proteins makes it the most promising target for anti-DENV drug discovery, although none of NS2B-NS3 inhibitors have been approved for the market so far. In this study, potent NS2B-NS3 covalent inhibitors were discovered via chemical modification of a published covalent inhibitor WSL-01 (IC = 129 nM), yielding promising analogs WSL-75 and WSL-84 (IC = 24.8 nM and IC = 32.89 nM, respectively) with more than 10-fold increased enzymatic activities compared to the lead compound, and no evident cellular toxicity was observed. Further comprehensive structure-activity relationship analysis through covalent docking and molecular dynamics simulation provides informative understanding of the binding modes of covalent inhibitors targeting NS2B-NS3, which would be beneficial for novel NS2B-NS3 inhibitory development.