Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

The singlet oxygen and carotenoid interaction.

P F Conn1, W Schalch, T G Truscott

  • 1Department of Chemistry, University of Keele, U.K.

Journal of Photochemistry and Photobiology. B, Biology
|October 1, 1991
PubMed
Summary

Lycopene efficiently quenches singlet oxygen (O2(1 delta g)) more than beta-carotene. Carotenoid quenching efficiency increases with conjugated double bonds and is influenced by solvent viscosity and epoxide groups.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Does iron chelation by eumelanin contribute to the ethnic link with maternal mortality?

European journal of obstetrics, gynecology, and reproductive biology·2022
Same author

Comment on: What is meso-zeaxanthin, and where does it come from?

Eye (London, England)·2013
Same author

The carbonate radical: its reactivity with oxygen, ammonia, amino acids, and melanins.

The journal of physical chemistry. A·2008
Same author

Direct observation of NH2* reactions with oxygen, amino acids, and melanins.

The journal of physical chemistry. A·2008
Same author

[Antioxidant micronutrients and cataract. Review and comparison of the AREDS and REACT cataract studies].

Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft·2003
Same author

Antioxidant inhibition of porphyrin-induced cellular phototoxicity.

Journal of photochemistry and photobiology. B, Biology·2002

Area of Science:

  • Photochemistry
  • Biophysics
  • Organic Chemistry

Background:

  • Singlet oxygen (O2(1 delta g)) is a reactive oxygen species implicated in various biological processes.
  • Carotenoids are natural pigments with antioxidant properties, known to quench singlet oxygen.
  • Understanding the factors governing carotenoid-singlet oxygen interactions is crucial for their biological roles.

Purpose of the Study:

  • To determine the second-order rate constants (kQ) for singlet oxygen quenching by various carotenoids.
  • To investigate the influence of carotenoid structure (conjugation, substituents) and solvent properties (viscosity) on quenching efficiency.
  • To compare the quenching efficiency of different carotenoids, including lycopene and beta-carotene.

Main Methods:

  • Time-resolved luminescence spectroscopy was employed to measure quenching rate constants.

Related Experiment Videos

  • Experiments were conducted at room temperature in benzene and toluene solvents.
  • A series of C40 carotenoids and xanthophylls with varying structures were studied.

    • Main Results:

    • Lycopene exhibited the highest quenching efficiency among C40 pigments studied, though less than previously reported.
    • Quenching rate constants (kQ) were inversely proportional to solvent viscosity, suggesting thermodynamic involvement.
    • Quenching efficiency increased with the number of conjugated carbon-carbon double bonds (e.g., kQ(C60) > kQ(C50) > kQ(C40)).
    • Epoxide groups on xanthophylls appeared to enhance reactivity with singlet oxygen compared to carbonyl or hydroxyl substituents.

    Conclusions:

    • Carotenoid structure, particularly the extent of conjugation and the presence of epoxide groups, significantly impacts singlet oxygen quenching efficiency.
    • Solvent viscosity plays a role, indicating that thermodynamic factors are involved in the quenching process.
    • These findings contribute to a deeper understanding of carotenoid antioxidant mechanisms and their interactions with reactive oxygen species.