Cited by 74Phytochemicals and Antioxidant ActivitiesNitric Oxide and Endothelin EffectsFree Radicals and Antioxidants

Oxidation of quercetin by salivary components. Quercetin-dependent reduction of salivary nitrite under acidic conditions producing nitric oxide

Takahama, Umeo, Oniki, Takayuki, Hirota, Sachiko·2002·Journal of Agricultural and Food Chemistry

Abstract

Under acidic conditions, nitrite is protonated to nitrous acid (pK(a) = 3.2-3.4) that can be transformed into nitric oxide by self-decomposition and reduction. When sodium nitrite was mixed with quercetin at pH 1-2, quercetin was oxidized producing nitric oxide. In addition to quercetin, kaempferol and quercetin 4'-glucoside were also oxidized by nitrous acid, but oxidation of apigenin, luteolin, and rutin was slow compared to oxidation of the above flavonols. These results suggested that flavonols, which have a free hydroxyl group at carbon position 3, can readily reduce nitrous acid to nitric oxide. When the pH of saliva was decreased to 1-2, formation of nitric oxide was observed. The nitric oxide formation was enhanced by quercetin, and during this process quercetin was oxidized. These results indicate that there is a possibility of reactions between phenolics and nitrous acid derived from salivary nitrite in the stomach.

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Crossref · 10.1021/jf011697q

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  • NO production in the stomach is greatly enhanced in the presence of dietary polyphenols and ascorbic acid.

    “the NO production in the stomach is greatly enhanced in the presence of dietary polyphenols [24] and ascorbic acid [15]”

    From NO-Rich Diet for Lifestyle-Related Diseases (2015) · cites this paper as [24]

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Authors
Takahama, U., Oniki, T., & Hirota, S.
Affiliations
Kyushu Women's University (JP)
Corresponding author
Takahama, Umeo
Venue
Journal of Agricultural and Food Chemistry
Published
2002-06-12
Volume
50
Issue
15
Pages
4317-4322
ISSN
  • 0021-8561 (ISSN-L)
  • 1520-5118
OpenAlex
W2034780811
Cited by
74
References
28
Citations by year
2026: 5 · 2024: 1 · 2022: 1 · 2021: 3 · 2020: 3 · 2019: 1 · 2018: 1 · 2017: 4 · 2016: 2 · 2015: 3 · 2014: 5 · 2013: 4 · 2012: 3
FWCI
1.93
Type
journal article
Language
en
Open access
closed
Locations
  • Journal of Agricultural and Food Chemistry (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Biochemistry › Phytochemicals and Antioxidant Activities
  • Health Sciences › Medicine › Physiology › Nitric Oxide and Endothelin Effects
  • Physical Sciences › Chemistry › Organic Chemistry › Free Radicals and Antioxidants
Keywords
quercetin, salivary nitrite, nitric oxide, nitrous acid, kaempferol, apigenin, luteolin, rutin, low pH, salivary pH, gastric acid
MeSH terms
Flavonoids, Humans, Hydrogen-Ion Concentration, Kinetics, Nitric Oxide, Nitrous Acid, Oxidation-Reduction, Quercetin, Saliva, Sodium Nitrite, Kaempferols

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