Table 2.
Antibacterial effects of (−)-polyalthic acid (1), kaurenoic acid (2) and their derivatives. The IC50 values are in μg/ml. Positive controls were ampicillin (Enterococcus faecium) and chloramphenicol (MRSA)
| E. faecium | MRSA | |
|---|---|---|
| Compound 1 | 8.5 ± 0.4 | 8.9 ± 0.8 |
| Compound 1a | > 100 | > 100 |
| Compound 1b | > 100 | > 100 |
| Compound 1c | > 100 | > 100 |
| Compound 2 | 2.3 ± 0.2 | 3.4 ± 0.2 |
| Compound 2a | > 100 | > 100 |
| Compound 2b | > 100 | > 100 |
| Compound 2c | 59.7 ± 0.1 | 34.7 ± 2.5 |
| Compound 2d | > 100 | > 100 |
| Compound 2e | > 100 | > 100 |
| Positive control | 0.4 ± 0.1 | 1.2 ± 0.1 |