Oxidation of Ascorbic Acid in the Presence of Nitrites

Myshkin, A. E.; Konyaeva, V. S.; Гумаргалиева, К. З.; Moiseev, Yuri V.

doi:10.1021/jf940643w

Cited by 15 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been reported that nitric oxide formation can be measured using an oxygen electrode [18–20]. As a mechanism of nitric oxide formation by AA/nitrite systems under acidic conditions, reduction of nitrous acid by AA is possible [5–9]:

…”

Section: Resultsmentioning

confidence: 99%

“…Saliva, which contains nitrite (0.05–0.2 mM) (p K a =3.3) [1,2], is normally swallowed into the stomach and mixed with gastric juice, which contains ascorbic acid (AA) (0.05–0.3 mM) [3,4], and it is well known that nitrite is reduced by AA, producing nitric oxide under acidic conditions [5–9]. According to these reports, it is supposed that nitric oxide is formed when saliva is mixed with gastric juice.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen uptake during the mixing of saliva with ascorbic acid under acidic conditions: possibility of its occurrence in the stomach

et al. 2003

View full text Add to dashboard Cite

Human saliva, which contains nitrite, is normally mixed with gastric juice, which contains ascorbic acid (AA). When saliva was mixed with an acidic bu¡er in the presence of 0.1 mM AA, rapid nitric oxide formation and oxygen uptake were observed. The oxygen uptake was due to the oxidation of nitric oxide, which was formed by AA-dependent reduction of nitrite under acidic conditions, by molecular oxygen. A salivary component SCN 3 enhanced the nitric oxide formation and oxygen uptake by the AA/nitrite system. The oxygen uptake by the AA/nitrite/SCN 3 system was also observed in an acidic bu¡er solution. These results suggest that oxygen is normally taken up in the stomach when saliva and gastric juice are mixed. ß

show abstract

…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Oxygen uptake during the mixing of saliva with ascorbic acid under acidic conditions: possibility of its occurrence in the stomach

et al. 2003

View full text Add to dashboard Cite

show abstract

“…The results described here show that ascorbic acid may be a poor inhibitor of nitration or deamination by nitrite under acidic conditions such as those of the stomach. In neutral aqueous media, ascorbic acid reacts very slowly with nitrite, forming dehydroascorbic acid via a nitrosation reaction (32). The rate-limiting step is the formation of the nitrosating agent which is proposed to be either N 2 O 3 or H 2 NO 2 + (32).…”

Section: Discussionmentioning

confidence: 99%

“…The rate-limiting step is the formation of the nitrosating agent which is proposed to be either N 2 O 3 or H 2 NO 2 + (32). The reaction is highly pH-dependent, suggesting that nitrite accelerates vitamin C decay in fruit and vegetables under acidic storage conditions (32). Dahn et al (33) have observed that the rate of reaction between nitrite and ascorbic acid is slow at physiological concentrations of nitrite in acidic media due to the formation of N 2 O 3 .…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Nitrous Acid-Dependent Tyrosine Nitration and DNA Base Deamination by Flavonoids and Other Phenolic Compounds

Oldreive

Zhao

Paganga

et al. 1998

Chem. Res. Toxicol.

View full text Add to dashboard Cite

Exposure of tyrosine or DNA bases to acidic nitrite at low pH results in the nitration of tyrosine and the formation of base deamination products, respectively. At pH 1, hypoxanthine and xanthine are formed from the deamination of adenine and guanine, respectively, whereas under the same conditions, uracil is not detected. The yield of 3-nitrotyrosine derived from interaction of equimolar nitrite and tyrosine at pH 1 is approximately 50% of that obtained from equimolar peroxynitrite-tyrosine interactions at pH 7. 4. The ability of a range of plant phenolic constituents to prevent damage mediated by acidic nitrite was also examined in comparison with the activity of vitamin C. The epicatechin/gallate family of flavonols, constituents of green tea, red wine, etc., demonstrates the most extensive inhibitory properties against both tyrosine nitration and base deamination. The results also show that ascorbic acid is a poor inhibitor of nitration or deamination under acidic conditions such as those of the stomach. The ability of plant phenolics to scavenge reactive nitrogen species derived from acidic nitrite may contribute to the protective effects of tea polyphenols against gastric cancer.

show abstract

“…There is little doubt that antioxidants effectively inhibit the formation of nitrosamines by scavenging nitrite (Shenoy and Choughuley 1992, Myshkin et al. 1996, Rundlöf et al.…”

Section: Discussionmentioning

confidence: 99%

Wounding of Root or Basal Stalk Prior to Harvest Affects Pre‐harvest Antioxidant Accumulation and Tobacco‐specific Nitrosamine Formation during Air Curing of Burley Tobacco (Nicotiana tabacum L.)

Li¹,

Krauss²,

Hempfling³

2006

J Agronomy Crop Science

View full text Add to dashboard Cite

Wounding stresses were tested for their ability to induce an accumulation of antioxidants in harvested tobacco (Nicotiana tabacum L.) and for the reduction of tobacco-specific nitrosamines (TSNA) during subsequent air curing. Data indicated that root pruning of burley tobacco 1 week before harvest resulted in an increased accumulation of a-tocopherol, chlorogenic acid and rutin, compared with untreated plants. Wounding also increased total antioxidant capacity in both green and cured tobacco. Field experiments performed over 3 years showed a consistent decrease in nitrite concentration in leaves from wounded tobacco, and the reduction in TSNA was always associated with reduced levels of nitrite. Depending on climate and curing conditions, curing resulted in significant reductions in TSNA, compared with unwounded, control plants. Thus, the results suggested that higher endogenous antioxidants present during senescence and curing of wounding-stressed tobacco may affect the propensities of those tissues to inhibit TSNA formation by reaction with nitrite.

show abstract

Oxidation of Ascorbic Acid in the Presence of Nitrites

Cited by 15 publications

References 4 publications

Oxygen uptake during the mixing of saliva with ascorbic acid under acidic conditions: possibility of its occurrence in the stomach

Oxygen uptake during the mixing of saliva with ascorbic acid under acidic conditions: possibility of its occurrence in the stomach

Inhibition of Nitrous Acid-Dependent Tyrosine Nitration and DNA Base Deamination by Flavonoids and Other Phenolic Compounds

Wounding of Root or Basal Stalk Prior to Harvest Affects Pre‐harvest Antioxidant Accumulation and Tobacco‐specific Nitrosamine Formation during Air Curing of Burley Tobacco (Nicotiana tabacum L.)

Contact Info

Product

Resources

About