Identification of Novel Acylthiourea-Based PROTACs Exhibiting Broad-Spectrum Antiviral Activity against Enteroviruses

Abstract Enteroviruses are the primary cause of hand, foot, and mouth disease (HFMD). The absence of broad-spectrum antivirals, due to high serotypic and genetic diversity, greatly hampers effective treatment. In this study, we developed a novel type of acylthiourea-based proteolysis-targeting chimeras (PROTACs) to induce targeted protein degradation. Compound X14 was identified as a potent candidate. X14 showed strong anti-EV71 activity by inhibiting viral replication. It directly binds to the EV71 3D polymerase with higher affinity than ribavirin and causes proteasome-dependent degradation of the 3D protein. X14 demonstrated broad-spectrum activity against representative EV-A, EV-B, EV-C, and EV-D enteroviruses and exhibited superior in vivo efficacy compared to the parent compound. X14 is a PROTAC targeting EV71 3D polymerase, making it a promising antiviral candidate and chemical tool for HFMD.