Figure 3.

Dose-response curves and the structures of the four hits: angeloylgomisin O (A), schisandrin B (B), procyanidin (C), and oleanonic acid (D) for inhibiting SARS-CoV-2 S pv (ct19) infection. (Right) The structure of each hit. Caco-2 cells were seeded at a density of 2.4 × 10⁴ cells per well in 96-well plates. After overnight incubation, cell monolayers were treated with hits; 1 h later, cells were infected with different pv, and the supernatant was removed 1 h post-infection. The infected cells were lysed 23 h later, and the luciferase activities were measured. Cell viability was evaluated using the MTT assay. Hits at the indicated concentrations were added to pre-seeded Caco-2 cells in 96-well plates. Twenty-four hours later, cell viability was measured. Data are represented as the mean ± standard deviation (SD) from three to four experiments.