Table 1.
IC50 values of the test compounds for ability to inhibit PDE5, PDE11 and the growth of human HT29 colon tumor cells. The results are the average of at least 3 experiments each made in triplicate.
| Cpd. | IC50 HT29 growth (μM) | IC50 PDE5, cGMP (μM) | IC50 PDE11, cGMP (μM) | IC50 PDE11, cAMP (μM) |
|---|---|---|---|---|
| I | 15.5 ± 1.03 | 3.9 ± 1.09 | > 100 | > 100 |
| II | > 20 | > 100 | > 100 | > 100 |
| III | > 20 | 14.3 ± 1.09 | > 100 | > 100 |
| IV | > 20 | 17.4 ± 1.09 | > 100 | > 100 |
| V | 2.5 ± 1.02 | 5.0 ± 1.14 | > 100 | > 100 |
| VI | 11 ± 1.03 | > 100 | > 100 | > 100 |
| VII | 17 ± 1.02 | > 100 | > 100 | > 100 |
| VIII | > 20 | 87.4 ± 1.10 | > 100 | > 100 |
| IX | > 20 | 78.6 ± 1.14 | > 100 | > 100 |
| X | > 20 | > 100 | > 100 | > 100 |
| Tadalafil | > 50 | 0.004 ± 0.001 | 0.782 ± 0.001 | > 2 |
| Exisulind | 364.8 ± 1.04 | 295 ± 1.11 | > 300 | > 300 |