N-Demethylation of troleandomycin, erythromycin, and roxithromycin and its metabolites by liver microsomes from human samples HL-4, HL-16, and HL-18
| HL-4 | HL-16 | HL-18 | |
|---|---|---|---|
| P450 content (nmol/mg of protein) | |||
| P450 | 0.55 | 0.31 | 0.35 |
| CYP3A4 | 0.25 | 0.05 | 0.10 |
| N-Demethylation activity (nmol/min/mg of protein) | |||
| Troleandomycin | 2.35 | 1.10 | 1.87 |
| Erythromycin | 1.54 | 1.07 | 1.37 |
| Roxithromycin | 0.83 | 0.65 | 0.69 |
| M1 | 0.90 | 0.71 | 0.84 |
| M2 | 0.85 | 0.63 | 0.79 |
| M3 | 1.12 | 0.87 | 0.99 |
Macrolide antibiotics (1 mM) were incubated with human liver microsomes (0.75 mg of protein/ml) at 37°C for 10 min.