Related Experiment Videos
From free radicals to electronically excited species
Free Radical Biology & Medicine
|July 1, 1995
Summary
Metabolizing biologically important compounds can create free radicals and excited species. These excited states, often overlooked, should be investigated alongside radicals for a complete understanding of xenobiotic effects.
Area of Science:
- Biochemistry
- Chemical Biology
- Toxicology
Background:
- Metabolism of biologically significant compounds can produce free radicals.
- These processes can also generate electrically excited products, often in a triplet state.
- Peroxidases, prostaglandin-H synthase, and lipoxygenase are enzymes involved in these reactions.
Purpose of the Study:
- To highlight the generation of excited species during xenobiotic metabolism.
- To emphasize the importance of considering excited species in biological effect analysis.
- To suggest methods for detecting and analyzing these excited species.
Main Methods:
- Review of chemical and biological processes involving free radicals and excited states.
- Discussion of enzymatic catalysis by peroxidases, prostaglandin-H synthase, and lipoxygenase.
- Consideration of radical and excited species reactivity and similarity.
Main Results:
- Chemiluminescence can arise from peroxyl and alkoxyl radicals or excited states from dioxetanes.
- Excited carbonyls can be formed by enzymes like prostaglandin-H synthase and lipoxygenase.
- Excited species share chemical similarities with radicals due to their biradical nature.
Conclusions:
- The generation of excited species during xenobiotic metabolism is a significant but often overlooked phenomenon.
- Analysis of biological effects should include investigation of these excited species.
- Direct/sensitized emission or photochemical transformation can be used to detect excited species.