Evaluation of a novel high-throughput assay for cytochrome P450 2D6 using 7-methoxy-4-(aminomethyl)-coumarin

Eur J Pharm Sci. 2000 Dec;12(2):151-8. doi: 10.1016/s0928-0987(00)00150-0.


We recently reported on the design, synthesis and characterisation of a novel and selective substrate of human cytochrome P450 2D6 (CYP2D6), 7-methoxy-4-(aminomethyl)-coumarin (MAMC). Here, we describe a high-throughput microplate reader assay, which makes use of MAMC as a fluorescent probe for determining the inhibition and activity of CYP2D6 in heterologously expressed systems and human liver microsomes. The high-throughput screening (HTS) assay can be used both in an end-point and real-time configuration, and is easy to use, rapid and sensitive. In addition, end-point measurements by means of flow injection analysis have also successfully been performed. The HTS-assay was validated by performing inhibition experiments for several low- and high-affinity ligands (n=6) of CYP2D6, and comparing the findings to those obtained with the standard O-demethylation assay of dextromethorphan. The results indicate that all compounds tested display competitive inhibition in both the MAMC and dextromethorphan assay, and the K(i) values reveal a very good correlation (R(2)=0.984) between the two assays. To further demonstrate the usefulness of the HTS-assay, IC(50) values of a series of five N-substituted analogs of 3, 4-methylenedioxyamphetamine for CYP2D6 have been determined. The results obtained demonstrate that the current HTS-assay represents a significant improvement over previous assays, with a higher turnover of MAMC and a higher selectivity for CYP2D6.

MeSH terms

  • Calibration
  • Cell Line
  • Coumarins / pharmacokinetics*
  • Cytochrome P-450 CYP2D6 / analysis
  • Cytochrome P-450 CYP2D6 / metabolism*
  • Dextromethorphan / pharmacokinetics*
  • Humans
  • Kinetics
  • Microsomes / enzymology*
  • Microsomes, Liver / enzymology*
  • Recombinant Proteins / analysis
  • Recombinant Proteins / metabolism
  • Sensitivity and Specificity
  • Spectrometry, Fluorescence / methods
  • Substrate Specificity


  • 7-methoxy-4-(aminomethyl)coumarin
  • Coumarins
  • Recombinant Proteins
  • Dextromethorphan
  • Cytochrome P-450 CYP2D6