Table 2.
Antiviral activity of betulin derivatives against the cytopathogenic bovine orphan virus (ECBO) strain LCR-4 in adenocarcinoma epithelial (A549) cells.
| Compound | CC50 (μg/mL) | EC50 (μg/mL) | SI |
|---|---|---|---|
| 5e | 10.3 | 1.0 | 10.3 |
| 5f | 100.0 | 5.0 | 20.0 |
| 5h | 27.7 | 0.5 | 55.5 |
| 5j | 100.0 | 5.0 | 20.0 |
| 6f | 100.0 | 5.0 | 20.0 |
| 6h | 29.8 | 0.25 | 0.25 |
| Betulin 1 | 18.5 | 0.5 | 37.0 |
| Ribavirin | 100.0 | 10.0 | 10.0 |
CC50—50% cytotoxic concentration; concentration required to reduce A549 cells viability by 50%. EC50—50% effective concentration; concentration required to inhibit ECBO cytopathic effect in A549 cells by 50%. SI—selectivity index, or ratio of CC50 to EC50.