The role of biotransformation and bioactivation in toxicity

  • Wolfgang Dekant
Part of the Experientia Supplementum book series (EXS, volume 99)


Biotransformation is essential to convert lipophilic chemicals to water-soluble and readily excretable metabolites. Formally, biotransformation reactions are classified into phase I and phase II reactions. Phase I reactions represent the introduction of functional groups, whereas phase II reactions are conjugations of such functional groups with endogenous, polar products. Biotransformation also plays an essential role in the toxicity of many chemicals due to the metabolic formation of toxic metabolites. These may be classified as stable but toxic products, reactive electrophiles, radicals, and reactive oxygen metabolites. The interaction of toxic products formed by biotransformation reactions with cellular macromolecules initiates the sequences resulting in cellular damage, cell death and toxicity.


Cytochrome P450 Enzyme Epoxide Hydrolase Reactive Oxygen Metabolite Glutathione Conjugation Mercapturic Acid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Birkhäuser Verlag/Switzerland 2009

Authors and Affiliations

  • Wolfgang Dekant
    • 1
  1. 1.Department of ToxicologyUniversity of WürzburgWürzburgGermany

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