scholarly journals THE EFFECT OF ASCORBIC ACID OXIDATION ON THE INCORPORATION OF SULFATE BY SLICES OF CALF COSTAL CARTILAGE

1958 ◽  
Vol 42 (2) ◽  
pp. 303-318 ◽  
Author(s):  
S. J. Klebanoff ◽  
D. D. Dziewiatkowski ◽  
G. J. Okinaka
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Sodium Azide ◽  
Costal Cartilage ◽  
Dehydroascorbic Acid ◽  
Inhibitory Effect ◽  
Considerable Extent ◽  
Acid Oxidation ◽  
Marked Inhibition ◽  
Production Of Hydrogen

A marked inhibition of the incorporation of S35-sulfate by normal calf costal cartilage was produced by potassium ascorbate in the presence of catalytic amounts of cupric ions. The effect of the various components of the ascorbic acid oxidizing system (potassium ascorbate, cupric ions, cuprous ions, hydrogen peroxide, dehydroascorbic acid) was investigated. The results of experiments in which hydrogen peroxide, catalase, or sodium azide were used singly or in combination suggest that the inhibition produced by the ascorbic acid oxidizing system is due, to a considerable extent, to the production of hydrogen peroxide. Dehydroascorbic acid was also found to inhibit the incorporation of S35-sulfate by cartilage slices. However, the gradual fall in pH which resulted from the addition of dehydroascorbic acid could account to a large extent for the inhibitory effect observed because the incorporation of S35-sulfate by cartilage slices decreases sharply as the pH is lowered. The incorporation of S35-sulfate by cartilage slices is inhibited also by increasing the concentration of phosphate.

A theoretical study of ascorbic acid oxidation andHOO˙/O2˙−radical scavenging

2017 ◽  
Vol 15 (20) ◽  
pp. 4417-4431 ◽  
Author(s):  
Yi-Jung Tu ◽  
David Njus ◽  
H. Bernhard Schlegel
Keyword(s):  
Ascorbic Acid ◽  
Theoretical Study ◽  
Radical Scavenging ◽  
Dehydroascorbic Acid ◽  
Acid Oxidation ◽  
Acid Radical

Ascorbate radical disproportionates by forming a dimer, cyclizing and dissociating to yield ascorbic acid and the most stable hydrated, bicyclic form of dehydroascorbic acid; radical scavenging by ascorbate radical can proceed by a similar mechanism.

scholarly journals Oxidation of L-Ascorbic Acid in the Presence of the Copper-Binding Compound from Methanotrophic Bacteria Methylococcus capsulatus (M)

Biomimetics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 48
Author(s):  
Lidia V. Avdeeva ◽  
Rudolf I. Gvozdev
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Rate Constant ◽  
Copper Complex ◽  
Ascorbate Oxidase ◽  
Acid Oxidation ◽  
Copper Binding ◽  
Methylococcus Capsulatus ◽  
Oxidation Stress ◽  
Noncatalytic Reaction

The oxidation of ascorbic acid by air oxygen and hydrogen peroxide in the presence of the copper-binding compound (cbc) from bacteria Methylococcus capsulatus (M) was studied. The rate constant of ascorbic acid oxidation by air oxygen in the presence of the copper complex with cbc from M. capsulatus (M) was shown to be 1.5 times higher than that of the noncatalytic reaction. The rate constant of ascorbic acid oxidation by hydrogen peroxide in the presence of the copper complex with cbc from M. capsulatus (M) decreased by almost one-third compared to the reaction in the absence of the copper complex with cbc. It was assumed that cbc can be involved in a multilevel system of antioxidant protection and can protect a bacterial cell from oxidation stress. Thus, the cbc is mimetic ascorbate oxidase in the oxidation of ascorbic acid by molecular oxygen.

Interference by ascorbic acid in test systems involving peroxidase. I. Reversible indicators and the effects of copper, iron, and mercury.

1982 ◽  
Vol 28 (4) ◽  
pp. 578-588 ◽  
Author(s):  
R H White-Stevens
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Lag Time ◽  
Inhibitory Effect ◽  
Enzyme Concentration ◽  
Citrate Buffer ◽  
Test Systems ◽  
Reagent Strips ◽  
High Concentrations ◽  
Reflectance Measurements

Abstract I describe the mechanism whereby ascorbic acid can hamper test systems involving a peroxide-generating system, peroxidase, and a benzidine-type indicator. In test media such as urines, abnormally high concentrations of ascorbic acid may give rise to false negatives in the determination of analytes such as glucose. Absorbance measurements in solution or reflectance measurements on commercially available paper reagent strips demonstrate either inhibition of visible activity by ascorbic acid or a lag time in the development of oxidized indicator color. The duration of the lag time is proportional to the ascorbic acid concentration, is inversely proportional to the enzyme concentration, and is also affected by concentrations of hydrogen peroxide and o-tolidine indicator. The same results were seen in both citrate buffer pH 5 and phosphate buffer pH 7. Because the complete system (o-tolidine indicator, hydrogen peroxide, and peroxidase) must be present if the ascorbate is to be oxidized rapidly, this indicates that ascorbic acid inhibits color development by re-reducing oxidized indicator as fast as it is formed; the o-tolidine then acts catalytically in oxidizing ascorbic acid. Added Cu2+ and Fe3+, both known to react with ascorbic acid, had measurable but small effects on the system. In contrast, Hg2+ abolished the ascorbic acid-elicited lag time, even when present in near-stoichiometric concentration. Hg2+ showed little inhibitory effect on the activity of either glucose oxidase or peroxidase. Presumably it rapidly oxidizes ascorbic acid to dehydroascorbate. The reaction of mercuric ion with ascorbate was measured by reflectance measurements of paper reagent strips in addition to absorbance measurements of solution assays; equivalent results were obtained. Incorporation of Hg2+ into reagent strips can thus render both strips and solution diagnostic tests insensitive to interfering substances such as ascorbic acid.

Variation in ascorbic acid oxidation routes in hydrogen peroxide and cupric ion solution as determined by GC/MS

1994 ◽  
Vol 66 (3) ◽  
pp. 345-350 ◽  
Author(s):  
John C. Deutsch ◽  
C. R. Santhosh-Kumar ◽  
Kathryn L. Hassell ◽  
J. Fred. Kolhouse
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Acid Oxidation ◽  
Cupric Ion
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