ABSTRACT Antivirals are urgently needed to combat the global SARS-CoV-2/COVID-19 pandemic, supplement existing vaccine efforts, and target emerging SARS-CoV-2 variants of concern. Small molecules that interfere with binding of the viral spike receptor binding domain (RBD) to the host angiotensin-converting enzyme II (ACE2) receptor may be effective inhibitors of SARS-CoV-2 cell entry. Here, we screened 512 pure compounds derived from natural products using a high-throughput RBD/ACE2 binding assay and identified (–)-hopeaphenol, a resveratrol tetramer, in addition to vatalbinoside A and vaticanol B, as potent and selective inhibitors of RBD/ACE2 binding and viral entry. For example, (–)-hopeaphenol disrupted RBD/ACE2 binding with a 50% inhibitory concentration (IC 50 ) of 0.11 μM, in contrast to an IC 50 of 28.3 μM against the unrelated host ligand/receptor binding pair PD-1/PD-L1 (selectivity index, 257.3). When assessed against the USA-WA1/2020 variant, (–)-hopeaphenol also inhibited entry of a VSVΔG-GFP reporter pseudovirus expressing SARS-CoV-2 spike into ACE2-expressing Vero-E6 cells and in vitro replication of infectious virus in cytopathic effect and yield reduction assays (50% effective concentrations [EC 50 s], 10.2 to 23.4 μM) without cytotoxicity and approaching the activities of the control antiviral remdesivir (EC 50 s, 1.0 to 7.3 μM). Notably, (–)-hopeaphenol also inhibited two emerging variants of concern, B.1.1.7/Alpha and B.1.351/Beta in both viral and spike-containing pseudovirus assays with similar or improved activities over the USA-WA1/2020 variant. These results identify (–)-hopeaphenol and related stilbenoid analogues as potent and selective inhibitors of viral entry across multiple SARS-CoV-2 variants of concern.
【저자키워드】 COVID-19, SARS-CoV-2, coronavirus, natural products, Antiviral agents, stilbenoids, 【초록키워드】 ACE2, Vaccine, pandemic, Antiviral, variant, SARS-CoV-2 variant, variants of concern, Remdesivir, cytotoxicity, in vitro, viral entry, Receptor binding domain, activity, Replication, pseudovirus, RBD, resveratrol, small molecule, receptor, inhibitor, reporter, binding, SARS-CoV-2 spike, Angiotensin-converting enzyme, Cytopathic effect, Concentration, Infectious virus, reduction, Compound, viral spike, inhibitory concentration, effective inhibitor, USA-WA1/2020, selective, analogue, Host, effective, pseudovirus assay, identify, example, addition, inhibited, screened, interfere, expressing, SARS-CoV-2 cell, Vero-E6 cell, 【제목키워드】 B.1.351, B.1.1.7, natural, stilbenoid, SARS-CoV-2 USA-WA1/2020,