Table 1.
Binding affinity (μM) to heat shock protein 90 (HSP90) protein and cell growth inhibitory activity (μM) of the compounds.
| Binding Affinity (μM) | Cell Growth Inhibitory Activity (μM) | |||
|---|---|---|---|---|
| Compound | Binding HSP90 (FP) IC50 | NCI-H460 IC50 72 h | STO IC50 72 h | A431 IC50 72 h |
| 2a | n.a. | 0.7 ± 0.01 | n.d. | 0.2 ± 0.01 |
| 2b | n.a. | 3.2 ± 0.5 | n.d. | 3.1 ± 0.5 |
| 2c | n.a. | n.d. | n.d. | 0.46 ± 0.8 |
| 4 | >100 | >50 | >50 | >50 |
| 5 | n.a. | 4.8 ± 0.1 | 2.7 ± 0.8 | 1.36 ± 0.05 |
| 7 | 2.47 ± 0.09 | >50 | 46.9 | 46.9 |
| 8 | 3.7 ± 0.03 | n.d. | 0.26 ± 0.08 | 0.26 ± 0.40 |
| 10 | >100 | >50 | >50 | >50 |
| 17-AAG | 1.095 ±0.05 | 0.010 ± 0.002 | - | 0.069 ± 0.005 |
n.a. = non-available results since the compounds were autofluorescent; n.d. = not determined; 17-AAG = tanespimycin, 17-N-allylamino-17-demethoxygeldanamycin.