Table 2. In vitro anti-influenza virus activity and cytotoxicity of the active compounds.
| Compd | IC50 a (μM) | CC50 b (μM) | SI c | Compd | IC50 (μM) | CC50 (μM) | SI |
| 8c | >100 | ND | ND | 15a | 8.3 ± 1.3 | 188.1 ± 10.1 | 22.7 |
| 9a | 28.3 ± 2.6 | >200 | >7.1 | 15b | 19.2 ± 3.5 | 135.9 ± 6.3 | 7.1 |
| 9b | >100 | ND | ND | 15c | 15.5 ± 0.5 | >200 | >32.3 |
| 9c | 55.0 ± 4.1 | >200 | >3.6 | 15d | >100 | ND | ND |
| 9d | >100 | ND | ND | 16c | 40.5 ± 3.9 | >200 | >4.9 |
| 10a | >100 | ND | ND | 16d | >100 | ND | ND |
| 10b | >100 | ND | ND | Curcumin | 6.7 ± 1.2 | 48.3 ± 5.7 | 7.2 |
aConcentration inhibiting viral replication by 50%. The values are means of at least three independent determinations; the corresponding standard deviations are noted.
bConcentration causing 50% cytotoxicity.
cSelectivity index, defined as CC50/IC50.