Results 121 to 130 of about 5,060 (171)

Enzymatic Transformation of Dehydroascorbic Acid to Diketogulonic Acid

Nature, 1960
THE conversion of dehydroascorbic acid to diketogulonic acid has been studied in chemical systems1 ; but, as Harris2 has pointed out, definite evidence is not available for any enzymatically catalysed transformation.
C P, TEWARI, P S, KRISHNAN
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Dehydroascorbic Acid and Cell Division

Nature, 1970
Accumulated evidence seems to suggest that dehydroascorbic acid has a function in the control of mitotic activity.
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Volatile degradation products ofl-dehydroascorbic acid

Zeitschrift für Lebensmittel-Untersuchung und -Forschung, 1976
Volatile degradation products were isolated from a solution of L-dehydroascorbic acid in phosphate buffer solution of pH 2,4,6 and 8 heated under reflux for 3 h or left at 25 degrees C for 200 h. The products were identified by comparison of their gas chromatographic retention data, infra-red and mass spectra with those of authentic compounds.
J, Velí'sek, J, Davídek, V, Kubelka, Z, Zelinková, J, Pokorny   +4 more
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Reduction of dehydroascorbic acid by homocysteine

Biochimica et Biophysica Acta (BBA) - General Subjects, 2001
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.
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Interaction of mammalian hemoglobins with dehydroascorbic acid

Experientia, 1981
Reactive sulfhydryl groups of major hemoglobins from guinea-pig, rat and cat reduced dehydroascorbic acid to ascorbic acid leading to formation of intrachain disulfide bonds. Hybridization experiments indicated that the reduction was carried out by the alpha chain of cat hemoglobin.
S, Deb, S, Som, S, Basu, I B, Chatterjee
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Reduction of dehydroascorbic acid at low pH

Journal of Biochemical and Biophysical Methods, 2007
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.
Luka, Wechtersbach, Blaz, Cigić
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Pseudorotational analysis of the dehydroascorbic acids

Journal of Molecular Structure, 1986
Abstract The conformational behaviour of dehydro-L-ascorbic acid 1 and dehydro-D-arabo ascorbic acid 2 has been studied by NMR spectroscopy and by molecular mecanics calculations. The pseudorotational analysis of the furanose ring was carried out from the three vicinal HH couplings assuming that the ring is involved in a two-state conformational ...
J. Guilleme, E. Diez, M.M. Gomez, L. Garrigos, J. Zuluaga   +4 more
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Intestinal transport and metabolism of oxidized ascorbic acid (dehydroascorbic acid)

American Journal of Physiology-Gastrointestinal and Liver Physiology, 1988
The transport and metabolic properties of dehydroascorbic acid have been evaluated in the small intestine of one ascorbic acid-dependent animal species (guinea pig) and one ascorbic acid-synthesizing animal species (rat). Loops of guinea pig jejunum in vitro brought about net transepithelial absorption of L-[14C]dehydroascorbic acid with most of the ...
R C, Rose, J L, Choi, M J, Koch
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Effect of dehydroascorbic acid on ovalbumin

Journal of Agricultural and Food Chemistry, 1989
Etude de la durbidite de solution d'ovalbumine (OVA) en presence d'acide dehydroascorbique afin de comprendre le mecanisme de formation de derives de faible poids moleculaire. Essais avec l'acide ascorbique, dans les memes conditions. Effets de generateurs ou de pieges a radicaux libres sur l'evolution de la turbidite.
Kimio Nishimura, Masaru Ohtsuru, Kimitoshi Nigota   +2 more
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Dehydroascorbic acid as an anti-cancer agent

Cancer Letters, 2008
Three discoveries together point the way to a potential treatment for cancer. In 1982, Poydock and colleagues found that dehydroascorbic acid has the remarkable ability to eliminate the aggressive mouse tumours, L1210, P388, Krebs sarcoma, and Ehrlich carcinoma.
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