Table 2.
Experimental (pKiexp) and predicted (pKipred) parameters for selected P-gp inhibitors calculated from IC50 and ΔG values
| Compound | IC50 (μM) | pIC50 | Kiexp (μM) | pKiexp | ΔG (kcal*mol−1) | pKipred |
|---|---|---|---|---|---|---|
| GF120918 | 0.18±0.06 | 6.74 | 0.001 | 9.0 | −11.8 | 8.68 |
| Itraconazole | 0.95±0.28 | 6.02 | 0.008 | 8.09 | −9.6 | 7.06 |
| Ketoconazole | 1.34±0.28 | 5.87 | 0.012 | 7.92 | −9.8 | 7.21 |
| Astemizole | 2.27±0.54 | 5.64 | 0.02 | 7.69 | −10.1 | 7.34 |
| Quinidine | 9.40±2.98 | 5.03 | 0.083 | 7.08 | −8.7 | 6.40 |
| Verapamil | 8.07±3.53 | 5.09 | 0.071 | 7.15 | −8.03 | 5.91 |
Note: IC50 values presented as mean ± standard deviation.
Abbreviations: ΔG, Gibbs free energy of binding; Kiexp, experimental inhibition constant; IC50, half maximal inhibitory concentration; pIC50, negative decimal logarithm of half maximal inhibitory concentration; P-gp, P-glycoprotein; pKi, negative decimal logarithm of inhibition constant; pred, predicted.