THE IRREVERSIBLE TRANSFORMATION OF DEHYDROASCORBIC ACID
نویسندگان
چکیده
منابع مشابه
Ascorbic Acid Dehydroascorbic Acid C6 Dicarboxylic Acid
Dehydroascorbic acid is shown to be converted to 2-(threo-l,2,3-trihydroxypropyl)tartronic acid in aqueous alkaline solutions. The structure of the acid was determined by mass spectrometry of its acyclic Me3Si derivative. Mass spectrometric and chromatographic data are compared with those of related compounds. The acid is formed by a benzilic acid rearrangement of the intermediate 2,3-hexodiulo...
متن کاملReduction of dehydroascorbic acid by homocysteine.
To determine the reductive process of extracellular dehydroascorbic acid (DHA), molecules (homocysteine, homocysteine thiolactone, methionine, cysteine, and homoserine) were tested to identify those with the potential to reduce DHA to ascorbic acid (AA). Homocysteine (Hcy) was the most potent of the molecules tested. The efficacy of Hcy was compared with that of other molecules able to reduce D...
متن کاملReduction of dehydroascorbic acid at low pH.
Ascorbic acid and dehydroascorbic acid are unstable in aqueous solution in the presence of copper and iron ions, causing problems in the routine analysis of vitamin C. Their stability can be improved by lowering the pH below 2, preferably with metaphosphoric acid. Dehydroascorbic acid, an oxidised form of vitamin C, gives a relatively low response on the majority of chromatographic detectors, a...
متن کاملThe use of homocysteine in the estimation of dehydroascorbic acid.
Two main methods are in current use for the estimation of dehydroascorbic acid. In the one, developed by Roe and his colleagues (Roe & Kuether, 1943; Roe, Mills, Oesterling & Damron, 1948), the dehydroascorbic acid is condensed with 2:4-dinitrophenylhydrazine and the product treated with sulphuric acid to give a red colour, the intensity of which is measured photoelectrically. In a second techn...
متن کاملSpectrophotometric determination of ascorbic acid and dehydroascorbic acid.
We present a method for measuring ascorbic acid in methanol/trichloroacetic acid extracts prepared from human plasma after enzymatic oxidation of ascorbic acid to dehydroascorbic acid by ascorbate oxidase. Samples were assayed by spectrophotometrically monitoring the kinetics of the concentration-dependent absorbance changes of dehydroascorbic acid with phosphate-citrate-methanol buffers. Ascor...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1943
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)72147-9