TABLE 2

Rutaecarpine hydroxylation activities of human P450s expressed in E. coli

E. coli membranes expressing CYP1A1, CYP1A2, and CYP1B1 had 7-ethoxyresorufin O-deethylation activities of 41.7, 1.44, and 4.41 nmol/min/nmol P450, respectively. E. coli membranes expressing CYP2A6, CYP2C9, CYP2D6, CYP2E1, and CYP3A4 had oxidation activities toward its model substrates (as indicated in parentheses) of 0.32 (coumarin), 11.6 (tolbutamide), 3.20 (dextromethorphan), 4.10 (chlorzoxazone), and 13.6 (nifedipine) nmol/min/nmol P450. Results represent mean ± S.E.M. of three independent determinations with duplicate incubations.