L-ascorbic acid quenching of singlet delta molecular oxygen in aqueous media: generalized antioxidant property of vitamin C.

Abstract

L-ascorbic acid quenches singlet (1 delta g) molecular oxygen in aqueous media (pH 6.8 for [1H]H2O and pD 7.2 for [2H]D2O) as measured directly by monitoring (0,0) 1 delta g leads to 3 sigma-g emission at 1.28 micron. Singlet oxygen was generated at room temperature in the solutions via photosensitization of sodium chrysene sulfonate; this sulfonated polycyclic hydrocarbon was synthesized to provide a water soluble chromophore inert to usual dye-ascorbate photobleaching. A marked isotope effect is found; kHQ2O is 3.3 times faster than kDQ2O, suggesting ascorbic acid is chemically quenching singlet oxygen.

• Authors: P T Chou, A U Khan
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 115 Issue 3 Pg. 932-7 (Sep 30 1983) ISSN: 0006-291X [Print] United States
• PMID: 6313002 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Water
• Singlet Oxygen
• Deuterium
• Deuterium Oxide
• Ascorbic Acid
• Oxygen

Topics

• Ascorbic Acid
• Deuterium
• Deuterium Oxide
• Kinetics
• Oxidation-Reduction
• Oxygen
• Photochemistry
• Singlet Oxygen
• Water