Stickstoffmonoxid, Superoxid und Peroxynitrit: Radikalchemie im Organismus

Daiber, Andreas; Ullrich, Volker

doi:10.1002/1521-3781(200212)36:6<366::aid-ciuz366>3.0.co;2-b

Cited by 11 publications

(10 citation statements)

References 31 publications

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“…After mixing the three compounds, the single component absorption maxima disappeared, but a new absorption maximum was detected at 302.5 nm indicating the occurrence of a new compound (Figure 6D). According to Daiber and Ullrich, who described the formation of ONOO − or ONOOH by addition of nitrite to acidic H 2 O 2 solution (see Equations 4 and 5), ONOO − /ONOOH has an absorption maximum at 302 nm 24. Consequently, decrease of the concentrations of the educts H 2 O 2 and ${\rm NO}_{2}^{{-} } $ as it was demonstrated in Figure 5, and the appearance of a new absorption maximum at 302.5 nm (Figure 6D) suggested that the same reaction proceeded in our experiments.…”

Section: Resultsmentioning

confidence: 89%

“…Besides the formation of HNO 2 according to Equation 1, surplus protons (H + ) in a strong acidic environment can react with ${\rm NO}_{2}^{{-} } $ to nitrosooxidanium (${\rm H}_{2} {\rm NO}_{2}^{ + } $ ) which may break down to water and nitrosonium cation (NO + ) 15. NO + is known to react with several biomolecules, and with H 2 O 2 it can form the toxic ONOOH:15, 17, 24 …”

Section: Resultsmentioning

confidence: 99%

“…ONOOH or the corresponding anion peroxynitrite (ONOO − ) is described in the literature to oxidize lipids, fatty acids, and proteins directly 24–26. In acidic media, ONOO − exists in the non‐charged form (ONOOH) because of its p K a of 6.8 24, 27, 28. Presumably, this non‐charged ONOOH is able to pass the cell membrane.…”

Section: Resultsmentioning

confidence: 99%

“…Presumably, this non‐charged ONOOH is able to pass the cell membrane. At physiological pH, e.g., inside the cell, ONOOH could break down to oxidizing ${\rm HO}^{ \bullet } $ and ${\rm NO}_{2}^{ \bullet } $ within seconds:16, 24, 29, 30 …”

Section: Resultsmentioning

confidence: 99%

“…${\rm NO}^{ \bullet } $ is well soluble in water, too. In the presence of water, nitrous acid is generated from ${\rm NO}^{ \bullet } $ and O 2 :24 …”

Section: Resultsmentioning

confidence: 99%

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Estimation of Possible Mechanisms of Escherichia coli Inactivation by Plasma Treated Sodium Chloride Solution

Oehmigen

Winter

Hähnel

et al. 2011

Plasma Processes & Polymers

267

207

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Treatment of aqueous liquids by surface‐DBD in atmospheric air resulted in bactericidal activity of the liquid itself. A 7 min treatment of sodium chloride (NaCl) solution and its immediate addition to Escherichia coli resulted in a complete bacteria inactivation (≥7 log) after 15 min exposure time. With a 30 min delay between plasma treatment of liquid and its addition to the bacteria, bactericidal effect was reduced but still detectable. Nitrate (${\rm NO}_{2}^{{-} } $), nitrite (${\rm NO}_{2}^{{-} } $), and hydrogen peroxide (H2O2), respectively, as well as strong acidification are detected in plasma treated liquids and can explain this bactericidal activity partially. Combination of 1.5 mg · L−1 ${\rm NO}_{2}^{{-} } $ and 2.5 mg · L−1 H2O2 at pH 3 results in maximum 3.5 log E. coli reduction within 60 min. Plasma diagnostics and liquid analytics are combined with theoretical considerations to focus possible reaction channels of plasma–water interactions. Using FT‐IR, stable molecules like nitrous oxide (N2O), ozone (O3), carbon dioxide (CO2), and traces of nitric acid (HNO3) and/or peroxynitrous acid (ONOOH) were measured. Reactions of these molecules from the plasma/gas phase with the aqueous liquid can result in acidification and generation of H2O2, ${\rm NO}_{2}^{{-} } $, and ${\rm NO}_{3}^{{-} } $ or peroxynitrite (ONOO−), respectively, via reactions which are associated with the occurrence of several more or less stable but biologically active chemical intermediates like ${\rm NO}^{ \bullet } $ or nitrogen dioxide (${\rm NO}_{2}^{ \bullet } $). On the other hand, H2O2, ${\rm NO}_{2}^{{-} } $, and ${\rm NO}_{3}^{{-} } $/ONOO− could serve as starting reaction partners to generate ${\rm NO}^{ \bullet } $, ${\rm HO}^{ \bullet } $, ${\rm NO}_{2}^{ \bullet } $, or hydroxyl radicals (${\rm HOO}^{ \bullet } $) in the liquid.

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Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…${\rm NO}^{ \bullet } $ is well soluble in water, too. In the presence of water, nitrous acid is generated from ${\rm NO}^{ \bullet } $ and O 2 :24 …”

Section: Resultsmentioning

confidence: 99%

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