Lycorine Derivative Inhibits SARS‐CoV‐2 Replication by Reducing −1 Programmed Ribosomal Frameshifting via Targeting ZAP

ABSTRACT The ongoing evolution of SARS‐CoV‐2 and its immune‐evading variants underscores an urgent requirement for broad‐spectrum antiviral drugs. In this study, a series of lycorine derivatives was synthesized. This led to the identification of compound 7 as a promising antiviral candidate. Compound 7 exhibited potent inhibitory activity against SARS‐CoV‐2 and its variants, including Alpha, Beta, Delta, and Omicron, in vitro. The antiviral efficacy of compound 7 was then validated in vivo. Treatment with compound 7 significantly reduced viral loads and alleviated lung pathologies in SARS‐CoV‐2‐infected hamsters. Mechanistically, compound 7 directly targeted the short isoform of the zinc‐finger antiviral protein (ZAP‐S) and bound to specific residues (E111, E115, and F549). This result was confirmed using cellular thermal shift assays, bio‐layer interferometry, and mutagenesis studies. This interaction enhanced the ZAP‐S stability and disrupted –1 programmed ribosomal frameshifting (–1PRF), a critical process for viral polyprotein synthesis. The antiviral activity of compound 7 was ZAP‐S‐dependent, as ZAP‐S knockdown abolished its efficacy while overexpression enhanced it. These results established compound 7 as a novel antiviral candidate that can combat SARS‐CoV‐2 and its variants by targeting ZAP to inhibit –1PRF. This compound, therefore, represents a promising therapeutic strategy.