摘要：Sixteen compounds isolated from Zingiber aromaticum and showing concentration-dependent inhibition with IC50 values less than 100 μ M , were analyzed for their possibility of time-, concentration-, and NADPH-dependent inhibition of CYP3A4 and four were analyzed for CYP2D6. All seven kaempferol glycosides and two kaempferol derivatives (4, 5, 8—14) appear to be the mechanism-based inhibitors of CYP3A4 enzyme in which the inhibition is irreversible and driven by the catalytic process. The other compounds showed no NADPH-dependent inhibition or reversible inhibition, and thus do not appear to be mechanism-based inhibitors. K I values for compounds 4, 5, 8—14 were in the range of 2.21—27.01 μ M , whereas the k inact values were 0.23—0.65 min−1. Kaempferol-3- O -(2,3,4-tri- O -acetyl-α- L -rhamnopyranoside) (5) was found to be the most potent CYP3A4 inactivator with K I and k inact values of 2.21 μ M and 0.45 min−1, respectively.
