Table 3.
Summary of the MS/MS fragmentation patterns of atRA and atRA-d5 metabolites formed by CYP26A1. The metabolites that are also oxidized to the same products when incubated separately with CYP26A1 are also listed. The five most abundant fragments that where also ≥ 10 % abundance are listed.
| Metabolite | rt (min) |
Parent m/z | Fragment m/z (% abundance) |
Formed from |
|---|---|---|---|---|
| 4,16-(OH)2-RA | 10.4 | 331 | 257 (18), 239 (99), 201 (37), 137 (19), 119 (46) |
4-OH-RA |
| (OH)2-RA | 12.3 | 331 | 255 (69), 239 (100), 201 (17), 137 (26), 119 (49) |
4-OH-RA |
| 4-oxo-16-OH-RA | 12.3 | 329 | 255 (100), 240 (19), 211 (14), 137 (16), 135 (24) |
4-OH-RA and 4-oxo-RA |
| 4,18-(OH)2-RA | 13.7 | 331 | 269 (68), 251 (45), 235 (25), 137 (53), 79 (22) |
4-OH-RA and 18-OH-RA |
| 4-oxo-18-OH-RA | 13.8 | 329 | 267 (75), 251 (31), 239 (22), 161 (83), 79 (100) |
4-OH-RA, 4-oxo-RA and 18-OH-RA |
| oxo-OH-RA | 14.2 | 329 | 267 (100), 229 (58), 163 (75), 161 (92), 131 (83) |
4-OH-RA and 18-OH-RA |
| 4-OH-RA | 17.8 | 315 | 253 (100), 151 (19), 119 (12), 79 (13) |
|
| 4-oxo-RA | 18.6 | 313 | 269 (100), 254 (76), 191 (11), 163 (21), 119 (33) |
4-OH-RA |
| 16-OH-RA | 19.0 | 315 | 241 (100), 119 (25) | |
| 18-OH-RA | 19.5 | 315 | 271 (38), 253 (82), 241 (17), 237 (67), 151 (36) |
|
| atRA-d5 incubation | ||||
| 4,16-(OH)2-RA | 10.4 | 335 | 261 (10), 243 (85), 204 (33), 119 (25), 79 (10) |
|
| (OH)2-RA | 12.3 | 335 | 243 (100), 204 (30), 140 (13), 119 (42), 79 (13) |
|
| 4-oxo-16-OH-RA | 12.3 | 332 | 258 (100), 243 (11), 178 (12), 140 (20), 138 (20) |
|
| 4,18-(OH)2-RA | 13.6 | 334 | 272 (77), 254 (42), 238 (31), 215 (27), 138 (50) |
|
| 4-OH-RA | 17.7 | 319 | 257 (100), 256 (12), 154 (14) |
|
| 4-oxo-RA | 18.5 | 316 | 272 (100), 257 (27), 254 (82), 165 (19), 120 (34) |
|
| 16-OH-RA | 18.9 | 320 | 246 (100), 119 (12) | |
| 18-OH-RA | 19.5 | 319 | 275 (32), 258 (14), 257 (89), 240 (36), 239 (22) |
|