TABLE 4
Mean (S.D., n = 6) percentage of dose excreted in urine as radiometabolites over 48 h, proposed chemical structure, and accurate mass of the MH+ and MNa+ molecular ions and two major daughter ions
Compound | % in 0–48 h Urine (S.D.) | Structures | Calculated Mass and Error (milliunits) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MH+ | MNa+ | F1 | F2 | ||||||
| M1a | 0.2 |
| 229.1552 (0.7) | 251.1372 (0.4) | 212.1287 (0.5) | 184.1338 (0.6) | |||
| M1b | 15.9 (7.4) |
| 229.1552 (0.9) | 251.1372 (–1.1) | 212.1287 (–0.4) | 184.1338 (–0.2) | |||
| M2 | Traces |
| 243.1345 (3.1) | 265.1164 (1.2) | 226.1079 (0.9) | 198.1130 (0.0) | |||
| M3 | 3.5 |
| 227.1396 (0.1) | 249.1215 (0.2) | 210.1130 (0.3) | 182.1181 (–0.1) | |||
| M4a (tentative) | 2.8 |
| 230.1392 (–0.2) | 252.1212 (0.7) | 212.1287 (0.8) | 184.1338 (0.4) | |||
| M4b | 15.2 (2.4) |
| 230.1392 (0.7) | 252.1212 (0.9) | 212.1287 (1.2) | 184.1338 (1.6) | |||
| M5 | 3.8 |
| 228.1236 (1.8) | 250.1055 (3.8) | 210.1130 (2.5) | 182.1181 (2.0) | |||
| M6 | 1.0 |
| 321.1484 (1.0) | 343.1304 (2.2) | 196.1338 (1.9) | 168.1388 (3.3) | |||
| M7 (brivaracetam) | 8.6 (3.8) |
| 213.1603 (1.7) | 235.1422 (–1.7) | 196.1338 (–1.8) | 168.1388 (–0.6) | |||
| M8 | 2.4 |
| 390.1764 (1.7) | 412.1584 (2.3) | 214.1443 (0.4) | 168.1388 (1.5) | |||
| M9 | 34.2 (6.1) |
| 214.1443 (–1.4) | 236.1263 (0.4) | 196.1338 (0.0) | 168.1388 (–0.3) | |||