Comparison of inactivation parameters for mechanism-based P450 inactivators (Chiba et al., 1995)
| Inactivator | Target P450 | Assay Method (Source) | kinact(min− 1) | Ki,app (μM) | Partition Ratio |
|---|---|---|---|---|---|
| L-754,394 | 3A4 | Testosterone 6β-hydroxylation (human liver microsomes) | 1.62 | 7.5 | 1.35 |
| Furafylline | 1A2 | (R)-warfarin 6-hydroxylation (human liver microsomes) | 0.87 | 23 | 3–6 |
| Gestodene | 3A4 | Nifedipine oxidation (human liver microsomes) | 0.39 | 46 | 9.0 |
| 6β-Thiotestosterone | 3A1/2 | Testosterone 6β-hydroxylation (rat liver microsomes) | 0.37 | 34 | NA10-a |
| Tienilic acid | 2C9 | Tienilic acid 5-hydroxylation (recombinant CYP 2C9) | 0.22 | 4.3 | 11.6 |
| N-methylcarbazole | 2B4 | Reduced CO-binding P450 spectrum (purified CYP 2B4) | 0.21 | 23 | NA |
| L-754,394 | 2D6 | Bufuralol 1′-hydroxylation (human liver microsomes) | 0.18 | 32 | 40.1 |
| N-methylcarbazole | 2B1 | Reduced CO-binding P450 spectrum (purified CYP 2B1) | 0.14 | 5.2 | NA |
↵10-a NA, Not available.