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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-3-2
pubmed:abstractText
A kinetic study of the quenching reaction of singlet oxygen ((1)O(2)) with pyrroloquinolinequinol (PQQH(2), a reduced form of pyrroloquinolinequinone (PQQ)), PQQNa(2) (disodium salt of PQQ), and seven kinds of natural antioxidants (vitamin C (Vit C), uric acid (UA), epicatechin (EC), epigallocatechin (EGC), ?-tocopherol (?-Toc), ubiquinol-10 (UQ(10)H(2)), and ?-carotene (?-Car)) has been performed. The second-order rate constants k(Q) (k(Q) = k(q) + k(r), physical quenching and chemical reaction) for the reaction of (1)O(2) with PQQH(2), PQQNa(2), and seven kinds of antioxidants were measured in 5.0 wt % Triton X-100 micellar solution (pH 7.4), using UV-visible spectrophotometry. The k(Q) values decreased in the order of ?-Car > PQQH(2) > ?-Toc > UA > UQ(10)H(2) > Vit C ? EGC > EC ? PQQNa(2). PQQH(2) is a water-soluble antioxidant. The singlet oxygen-quenching activity of PQQH(2) was found to be 6.3, 2.2, 6.1, and 22 times as large as the corresponding those of water-soluble antioxidants (Vit C, UA, EGC, and EC). Further, the activity of PQQH(2) was found to be 2.2 and 3.1 times as large as the corresponding activity of lipid-soluble antioxidants (?-Toc and UQ(10)H(2)). On the other hand, the activity of PQQH(2) is 6.4 times as small as that of ?-Car. It was observed that the chemical reaction (k(r)) is almost negligible in the quenching reaction of (1)O(2) by PQQH(2). The result suggests that PQQH(2) may contribute to the protection of oxidative damage in biological systems, by quenching (1)O(2).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1520-5118
pubmed:author
pubmed:issnType
Electronic
pubmed:day
9
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1705-12
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Kinetic study of the quenching reaction of singlet oxygen by Pyrroloquinolinequinol (PQQH(2), a reduced form of Pyrroloquinolinequinone) in micellar solution.
pubmed:affiliation
Department of Chemistry, Faculty of Science, Ehime University, Matsuyama 790-8577, Japan.
pubmed:publicationType
Journal Article, Comparative Study