The Oxidative Degradation of L-Ascorbic Acid via an a-Ketoaldehyde *
نویسندگان
چکیده
Dehydro-L-ascorbic acid, the oxidation product of L-ascorbic acid, is unstable in aqueous solution and decomposed by a hydrolytic disruption of its ring structure to 2,3-diketo-L-gulonic acid. It is shown by means of UV, 'H-, and 13C-NMR spectroscopy that after decarboxylation 3,4,5-trihydroxy-2-keto-L-valeraldehyde, an a-ketoaldehyde, is formed. This substance is oxidized further to L-erythroascorbic acid, coupled with a reduction of 2,3-diketo-L-gulonic acid to L-ascorbic acid.
منابع مشابه
Alleviation of Adverse Effects of Copper on Allium cepa L. by Exogenous Ascorbic Acid Application
Abstract In this study ameliorative effects of ascorbic acid (0.5 mM) on onion (Allium cepa L. cv. Red Azarshahr) under copper stress (Cu: 6.5 μM) were studied. Fresh weights of leaves and roots were reduced in seven week old plants under excess copper condition. Cu stress also reduced membrane stability index in leaves. There was a considerable increase in H2O2 content and lipid peroxidation i...
متن کاملAMELIORATION OF NICKEL TOXICITY IN SOYBEAN PLANTS BY GIBBERELLIN AND ASCORBIC ACID
The interactive effects of nickel (Ni) and ascorbic acid (AsA) and gibberellin (GA3) on soybean seedlings (Glycine max L. cv. Union × Elf) were examined. Seven-day old hydroponically-grown seedlings were exposed to NiCl2, 6H2O (0.5 mM), either with or without AsA (1 mM) or GA3 (0.05 mM) or AsA (1 mM) plus GA3 (0.05 mM), for five days. Nickel toxicity symptoms, such as formation of reddish-brown...
متن کاملEfficiency and Modeling of UV-Electropersulfate Process via Iron Electrode in the Degradation of Acid Blue 25 Dye Using Central Composite Design
Background: Dyes are resistant organic matter because they have an aromatic rings. Sulfate radical (SO4●-) is a powerful oxidative radical. The design via CCD, cause the process was done by high accurate and low-cost. The aim of this study was modeling of UV-EPS process to degradation of Acid Blue 25 dye via the CCD from aqueous. Methods: In this experiment study, used to a photoelectrochemical...
متن کاملUse of Fenton Reagent as Advanced Oxidative Process for Removal of Basic and Acid Red Dyes from Aqueous Solutions
In this study, the Fenton process was used to investigate the color removal efficiency of Acid Red 52 and Basic Red 18 dye solutions by direct chemical oxidation. Color and chemical oxygen demand (COD) was successfully removed more than 99% and up to 92% respectively. This article would provide an easy assessment of the viability of using Fenton reagent in acidic conditions, so it is a prom...
متن کاملInvestigation of the Effect of L-Ascorbic Acid on Class G Oil Well Cement
Various chemicals can have different effects on the properties of the cement slurry. In this paper, the different effects of L-ascorbic acid have been investigated on the important parameters of cement slurry made from class G oil well cement. These parameters included the amount of free fluid, rheological properties, Thickening Time, and compressive strength. Several cement slurries were made ...
متن کامل