Table 1.
Selected reaction monitoring (SRM) conditions for the major metabolites of the cytochrome P450 (P450) probe substrates and the uridine 5′-diphosphoglucuronosyl transferase (UGT) substrates used in all assays.
| Enzyme | Substrate * | Concentration (µM) |
Metabolite | SRM Transition (m/z) |
Collision Energy (eV) |
Polarity ** |
|---|---|---|---|---|---|---|
| CYP1A2 | Phenacetin | 20 | Acetaminophen | 152 > 110 | 25 | ESI+ |
| CYP2A6 | Coumarin | 1 | 7-Hydroxycoumarin | 163 > 107 | 17 | ESI+ |
| CYP2B6 | Bupropion | 3 | Hydroxybupropion | 256 > 238 | 10 | ESI+ |
| CYP2C8 | Amodiaquine | 0.1 | N-Desethylamodiaquine | 328 > 283 | 13 | ESI+ |
| CYP2C9 | Diclofenac | 1 | 4-Hydroxydiclofenac | 312 > 231 | 15 | ESI+ |
| CYP2C19 | S-Mephenytoin | 40 | 4-Hydroxymephenytoin | 235 > 150 | 15 | ESI+ |
| CYP2D6 | Dextromethorphan | 2 | Dextrorphan | 258 > 157 | 30 | ESI+ |
| CYP2E1 | Chlorzoxazone | 5 | 6-Hydroxychlorzoxazone | 184 > 120 | 18 | ESI− |
| CYP3A | Nifedipine | 0.2 | Dehydronifedipine | 345 > 284 | 30 | ESI+ |
| Midazolam | 0.1 | 1′-Hydroxymidazolam | 342 > 203 | 28 | ESI+ | |
| IS | Trimipramine | 0.07 | - | 295 > 100 | 17 | ESI+ |
| UGT1A1 | SN-38 | 0.5 | SN-38 glucuronide | 569 > 393 | 30 | ESI+ |
| UGT1A3 | CDCA | 2 | CDCA-24 glucuronide | 567 > 391 | 20 | ESI− |
| UGT1A4 | TFP | 0.5 | TFP-β-d-glucuronide | 584 > 408 | 30 | ESI+ |
| UGT1A6 | N-ASER | 1 | N-ASER-β-d-glucuronide | 395 > 219 | 10 | ESI+ |
| UGT1A9 | MPA | 0.2 | MPA-β-d-glucuronide | 495 > 319 | 25 | ESI− |
| UGT2B7 | Naloxone | 0.2 | Naloxone-β-d-glucuronide | 504 > 310 | 30 | ESI+ |
| IS | Estrone-β-d-glucuronide | 0.25 | - | 445 > 269 | 35 | ESI− |
* SN-38: 7-Ethyl-10-hydroxycamptothecin; CDCA: Chenodeoxycholic acid; TFP: Trifluoperazine; N-ASER: N-Acetylserotonin, and MPA: Mycophenolic acid. ** ESI: Electrospray ionization (ESI) interface to generate protonated ion [M+H]+ or deprotonated ion [M-H]−.