Figure 4.

In vitro antiviral activity of compounds M1–M5. The antiviral activities of the compounds were screened on NRC-03-nhCoV strain (Accession # EPI_ISL_430820) co-cultured with Vero-E6 cells. To determine the most effective and safer compounds, selectivity index (SI) was measured, and the compounds with high SI were selected. Values of inhibitory concentration 50% (IC₅₀) on viral cells and cytotoxic concentration 50% (CC₅₀) on Vero cells were calculated using nonlinear regression analysis by plotting log inhibitor concentration versus normalized response (variable slope). The data display the mean of cell viability percentage ± SEM of 4 replicas.