Table 2.
Inhibitory properties for yellow fever virus and dengue virus of the pyrazine containing compounds 20a–20n.
| Sr. No. | n | R1 | R2 | Heterocycle (positiona) | Dengue |
Yellow fever |
||||
|---|---|---|---|---|---|---|---|---|---|---|
| EC50 (μM) | CC50 (μM) | SI | EC50 (μM) | CC50 (μM) | SI | |||||
| 20a | 1 | F | H | Pyridin-4-yl (para) | 0.94 | >117.5 | >125 | 7.49 | >120 | 16 |
| 20b | 0 | F | p-Methyl | Pyridin-3-yl (ortho) | 0.94 | >117.5 | >125 | 13.10 | >118 | 9 |
| 20c | 1 | F | H | Pyridin-3-yl (para) | 2.99 | >115.1 | 38.5 | 8.90 | >116 | 13 |
| 20d | 0 | F | H | Pyridin-4-yl (ortho) | 11.71 | >117.1 | 10.4 | 8.22 | >123.3 | 15 |
| 20e | 0 | F | H | Pyridin-3-yl (ortho) | 23.19 | >120.5 | 5.2 | 47.53 | >119 | 2.5 |
| 20f | 1 | F | H | Pyridin-4-yl (ortho) | 40.70 | >118.0 | 2.9 | 21.29 | >127 | 6 |
| 20g | 0 | F | p-Methyl | Pyridin-4-yl (ortho) | >117 | >117 | 1 | 48.43 | >125 | 2.6 |
| 20h | 1 | CH3 | H | Pyridin-4-yl (para) | 16.60 | 74.7 | 4.5 | 36.83 | >110.5 | 3 |
| 20i | 0 | CH3 | p-Methyl | Pyridin-3-yl (ortho) | 10.55 | 47.5 | 4.5 | 18.41 | 75.5 | 4.1 |
| 20j | 1 | CH3 | H | Pyridin-3-yl (para) | 6.75 | >116.1 | 17.2 | 73.08 | >124 | 1.7 |
| 20k | 0 | CH3 | H | Pyridin-4-yl (ortho) | 4.71 | >122.5 | 26 | 12.46 | >125 | 10 |
| 20l | 0 | CH3 | H | Pyridin-3-yl (ortho) | 14.56 | >128.13 | 8.8 | >122 | >122 | 1 |
| 20m | 1 | CH3 | H | Pyridin-4-yl (ortho) | 57.86 | >118 | 2.04 | 70.61 | >120 | 1.7 |
| 20n | 0 | CH3 | p-Methyl | Pyridin-4-yl (ortho) | 11.90 | >119 | 10 | 30.93 | >117.5 | 3.8 |
a
Indicates the attachment point of the heterocycle on the phenyl ring.