L-ascorbic acid quenching of singlet delta molecular oxygen in aqueous media: generalized antioxidant property of vitamin C
L-ascorbic acid quenches singlet (/sup 1/..delta../sub g/) molecular oxygen in aqueous media (pH 6.8 for (/sup 1/H)H/sub 2/O and pD 7.2 for (/sup 2/H)D/sub 2/O) as measured directly by monitoring (0,0) /sup 1/..delta../sub g/ ..-->.. /sup 3/..sigma../sub g//sup -/ 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; k/sub Q//sup H/sub 2/O/ is 3.3 times faster than k/sub Q//sup D/sub 2/O/, suggesting ascorbic acid is chemically quenching singlet oxygen.
- Research Organization:
- Florida State Univ., Tallahassee
- DOE Contract Number:
- AS05-78EV05855
- OSTI ID:
- 5452195
- Journal Information:
- Biochem. Biophys. Res. Commun.; (United States), Journal Name: Biochem. Biophys. Res. Commun.; (United States) Vol. 115:3; ISSN BBRCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
400500 -- Photochemistry
ASCORBIC ACID
CHEMICAL REACTIONS
DEUTERIUM
HYDROGEN ISOTOPES
INFRARED SPECTRA
ISOMERS
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
NUCLEI
ODD-ODD NUCLEI
OXIDATION
SPECTRA
STABLE ISOTOPES
STEREOCHEMISTRY
VITAMINS