Table 2.
Effect of synthetic evodiamine analogues and their enantiomers on elevation of intracellular calcium in HEK-293 cells overexpressing either the human or rat (r) TRPV1 channel
| Compound | Structure | Efficacy (at 10 μM ± SE) | Potency EC50 ± SE | Desensitization of 0.1 μM capsaicin response IC50 ± SE | LogP ± SD |
|---|---|---|---|---|---|
| Evo 05 |  |
<10 | NA | NA | 1.48 ± 0.46 |
| 0 | NA | NA | |||
| Evo 15 |  |
0 | NA | NA | 1.48 ± 0.46 |
| r < 10 (8.5 ± 0.1) | NA | NA | |||
| Evo 06 |  |
70.0 ± 0.9 | 1.18 ± 0.08 μM | 1.13 ± 0.04 μM | 2.77 ± 0.50 |
| r 69.0 ± 3.2 | r 2.21 ± 0.40 μM | r 1.68 ± 0.17 μM | |||
| Evo 21 |  |
73.2 ± 1.7 | 3.06 ± 0.37 μM | 4.42 ± 0.09 μM | 2.77 ± 0.50 |
| r 62.2 ± 1.0 | r 5.42 ± 0.33 μM | r 5.26 ± 0.19 μM | |||
| Evo 09 |  |
10.6 ± 0.6 | 4.56 ± 1.16 μM | NA | 2.45 ± 0.51 |
| r < 10 (4.9 ± 0.1) | NA | NA | |||
| Evo 22 |  |
<10 (4.4 ± 0.6) | NA | NA | 2.45 ± 0.51 |
| r < 10 (6.5 ± 0.1) | NA | NA | |||
| Evo 23 |  |
41.7 ± 1.0 | 4.25 ± 0.50 μM | 7.31 ± 0.60 μM | 2.10 ± 0.72 |
| r 25.1 ± 0.6 | r 3.12 ± 0.37 μM | r 12.32 ± 0.74 μM | |||
| Evo 29 |  |
12.9 ± 1.0 | 9.76 ± 2.17 μM | NA | 2.10 ± 0.72 |
| r < 10 (9.5 ± 0.1) | NA | NA | |||
| Evo 28 |  |
17.8 ± 0.7 | 4.00 ± 0.83 μM | 34.06 ± 0.06 μM | 1.54 ± 0.85 |
| r 16.1 ± 0.5 | r 5.74 ± 0.1 μM | r 27.24 ± 7.10 μM | |||
| VR002 |  |
<10 (3.9 ± 0.1) | NA | NA | 1.91 ± 0.80 |
| r < 10 (7.4 ± 0.1) | NA | NA | |||
| VR001 |  |
<10 (1.0 ± 0.1) | NA | NA | 1.91 ± 0.80 |
| r < 10 (1.2 ± 0.1) | NA | NA | |||
| Evo 30 |  |
67.1 ± 0.9 | 2.01 ± 0.11 nM | 1.65 ± 0.15 nM | 3.96 ± 0.57 |
| r 72.1 ± 1.0 | r 2.45 ± 0.20 nM | r 1.61 ± 0.04 nM | |||
| Evo 31 |  |
51.2 ± 1.2 | 89.6 ± 14.5 nM | 0.18 ± 0.01 μM | 3.96 ± 0.57 |
| r 38.3 ± 0.8 | r 0.20 ± 0.02 μM | r 0.28 ± 0.01 μM | |||
| Evo 34 |  |
69.4 ± 0.8 | 25.9 ± 1.2 nM | 25.95 ± 0.44 nM | 3.79 ± 0.49 |
| r 69.5 ± 2.4 | r 89.1 ± 17.7 nM | r 31.5 ± 1.4 nM | |||
| Evo 35 |  |
41.8 ± 1.0 | 0.33 ± 0.04 μM | 0.36 ± 0.02 μM | 3.79 ± 0.49 |
| r 46.2 ± 1.9 | r 0.76 ± 0.16 μM | r 1.05 ± 0.13 μM | |||
| Evo 38 |  |
68.4 ± 0.6 | 59.2 ± 2.4 nM | 45.1 ± 2.0 nM | 2.59 ± 1.02 |
| r 50.2 ± 0.2 | r 76.1 ± 1.5 nM | r 80.1 ± 2.4 nM | |||
| Evo 39 |  |
58.3 ± 0.8 | 96.5 ± 6.1 nM | 0.12 ± 0.01 μM | 2.59 ± 1.02 |
| r 48.4 ± 1.1 | r 0.12 ± 0.02 μM | r 0.22 ± 0.03 μM | |||
| Evo 42 |  |
58.4 ± 0.6 | 0.21 ± 0.01 μM | 0.38 ± 0.01 μM | 3.26 ± 0.48 |
| r 48.9 ± 0.2 | r 0.87 ± 0.02 μM | r 0.64 ± 0.03 μM | |||
| VR007 |  |
60.4 ± 1.1 | 3.08 ± 0.19 μM | 2.67 ± 0.10 μM | 3.26 ± 0.48 |
| r 54.3 ± 2.1 | r 6.69 ± 0.94 μM | r 6.94 ± 0.58 μM | |||
| Evo 44 |  |
29.1 ± 1.9 | 5.43 ± 1.23 μM | 5.35 ± 0.20 μM | 2.01 ± 0.63 |
| r 34.3 ± 0.6 | r 5.43 ± 0.85 μM | r 6.24 ± 0.40 μM | |||
| VR003 |  |
<10 (4.3 ± 0.1) | 10 μM | 57.76 ± 6.63 μM | 2.01 ± 0.63 |
| r < 10 (5.6 ± 0.1) | NA | NA | |||
| Evo 46 |  |
55.5 ± 0.8 | 0.27 ± 0.01 μM | 0.47 ± 0.01 μM | 2.83 ± 0.64 |
| r 44.5 ± 0.6 | r 0.74 ± 0.03 μM | r 0.98 ± 0.04 μM | |||
| VR005 |  |
66.7 ± 0.5 | 6.99 ± 0.14 μM | 5.91 ± 0.09 μM | 2.83 ± 0.64 |
| r 51.7 ± 1.0 | r 6.85 ± 0.42 μM | r 10.33 ± 0.63 μM |
All tests were carried out at least in triplicate, and the compounds were tested also on HEK-293 cells not transfected with the TRPV1 receptor: none produced a significant elevation of intracellular [Ca2+] (not shown). The specificity of the receptor response for the substances that showed a substantial effect on intracellular [Ca2+], was verified also by pretreating the human or rat TRPV1 transfected cells for 5 min with the specific antagonist 5-iodo-resiniferatoxin at the concentration of 10 nM before the addition of the compound (1 μM), and full antagonism was observed in each case (not shown). NA = not active.