Table 1. Inhibition of M2 channel activity in Oocyte assay.
| Compounds | WT (%) | V27A (%) |
| 10 | 95 | 0 |
| 15 | 0 | n.a |
| 34 | 89 | 53.4 |
| 35 | 92 | 29.7 |
| 180 | 90.4 | 82.7 |
| 189 | 95.9 | 25.2 |
| 206 | 89.1 | 94.5 |
| 282 | 95.7 | 3.4 |
| 293 | 93.2 | 12.4 |
| 314 | 69.2 | 10.9 |
| 332 | 10.6 | 6.3 |
| 343 | 3.8 | 6.6 |
| 352 | 20.3 | 7.2 |
| 360 | 12.9 | 17.4 |
| 362 | 14.1 | 40 |
| Amantadine | 90.8 | 0 |
The inhibition efficiency of each compound was examined at the concentration of 100 μM. The values in the table represent how much the M2 channel activity is inhibited. WT, wild type M2 channel. V27A, M2 channel with V27 A mutation. The Oocyte assay was conducted as described previously [12].