Abstract
Deoxypodophyllotoxin is stereoselectively converted into epipodophyllotoxin by recombinant human cytochrome P450 3A4 (CYP3A4). Further kinetic analysis revealed that the Michaelis-Menten Km and Vmax for hydroxylation of deoxypodophyllotoxin by CYP3A4 at C7 position were 1.93 μM and 1.48 nmol/min/nmol, respectively. Deoxypodophyllotoxin was subjected to automated docking analysis in order to get better knowledge of the interaction between the CYP3A4 enzyme and the substrate, using the PatchDock algorithm with distance constraints. Automated docking showed that the β-hydrogen atom at C7 position is in the most appropriate binding orientation at the site of oxidation. The docking results are consistent with the experimental data for the bioconversion of deoxypodophyllotoxin into epipodophyllotoxin by CYP3A4. In addition, the effects of five lignans, deoxypodophyllotoxin, epipodophyllotoxin, podophyllotoxin, demethylenedeoxypodophyllotoxin, and demethylenepodophyllotoxin, on CYP3A4 were compared in order to investigate the influence of the methylenedioxy group on the biotransformation process, to give insight into the mode of metabolization and to explain inhibitory activity of lignans.
Original language | English |
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Pages (from-to) | 1171-1179 |
Number of pages | 9 |
Journal | European Journal of Medicinal Chemistry |
Volume | 43 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2008 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors would like to express their gratitude to F.P. Guengerich for providing us with the plasmids containing the genes encoding the human CYP3A4 and NADPH-P450 reductase and M.A. Castro for providing us with the lignan compounds. The research of H.J. Wolfson has been supported in part by the Israel Science Foundation (grant no. 281/05) and Hermann Minkowski Minerva Center for Geometry at Tel Aviv University. Financial support by the Huygens Program to N.P. Vasilev and Miiggenburg – Foundation is gratefully acknowledged.
Keywords
- Automated docking
- Cytochrome P450 3A4 (EC 1.14.14.1)
- Drug metabolism
- Epipodophyllotoxin
- Lignans