The monoethyl ester of meconic acid is an active site inhibitor of HCV NS5B RNA-dependent RNA polymerase.

Screening of the in-house sample collection for compounds with HCV NS5B RNA dependent RNA polymerase inhibition led to the identification of a new lead. Afterwards, we discovered that the screening lead, rather than containing the expected structure 1, was comprised of roughly a 1:1 mixture of meconic acid 2 and its monoethyl ester 3, with all inhibitory potency residing with 3. We propose that this compound shares critical common features for activity with alpha,gamma-diketoacids inhibitors previously discovered by our group. SAR around this molecule will be presented to provide an improved basis for structure-based ligand design.