Possible Formation of Dehydro-L-ascorbic Acid from 2,3-Diketo-L-gulonic Acid in an Aqueous Solution.
نویسندگان
چکیده
The reaction of 2,3-diketo-L-gulonic acid (DKG), which is one of the important intermediate products in the degradation of L-ascorbic acid (ASA) in both food and biological systems, in an aqueous solution was studied. The formation of a small amount of the γ-lactone, dehydro-L-ascorbic acid (DASA), from DKG was observed. This strongly suggests the chemical possibility of a reverse reaction in DASA hydrolysis which has been long believed to be irreversible.
منابع مشابه
The Oxidative Degradation of L-Ascorbic Acid via an a-Ketoaldehyde *
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-erythroa...
متن کاملBehavior of 3,4-endiol form of 2,3-diketo-gulono-delta-lactone formed from dehydro-L-ascorbic acid in deoxygenated and neutral solution.
The formation of L-ascorbic acid (AsA) was observed when dehydro-L-ascorbic acid (DHA) was dissolved in neutral buffer solutions under N2 bubbling at room temperature. The reduction of DHA was done with the lactonized compound of 2,3-diketo-L-gulonic acid (DKG), that is, the 3,4-endiol form of 2,3-diketo-gulono-delta-lactone (3,4-End DKGL). 3,4-End DKGL was formed from DHA or DKG (yield about 1...
متن کاملFormation of L-lyxonic and L-xylonic acids from L-ascorbic acid in rat kidney.
The enzymatic decarboxylation of n-ascorbic acid by rat kidney homogenates has been reported in an earlier study (1). It was shown that factors present in both the soluble and the particulate fractions were required for maximal activity. Evidence was presented suggesting that dehydro-L-ascorbic acid and 2,3-diketo-n-gulonic acid were intermediates in the decarboxylation of the vitamin. The reac...
متن کاملMetabolism of l-ascorbic acid, dehydro-l'ascorbic acid, and diketo-l-gulonic acid in the guinea pig.
The interrelationships of L-ascorbic acid (AsA) and dehydro-L-ascorbic acid (DHA) have been investigated both in viva and in vitro by numerous workers, with especial emphasis upon the conversion of DHA to AsA by the animal body (l-8). The conversion of DHA to diketo-L-gulonic acid (DKA) in vitro has been shown by Herbert and coworkers (3), by Borsook (l), and by Penney and Zilva (6), and this c...
متن کاملEffects of active oxygen scavengers on the peroxidation of linoleic acid catalyzed by dehydro-L-ascorbic acid or its degradation products.
The addition of 1,4-diazabicyclo-[2,2,2]octane (DABCO) (100 mM) or 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron) (1 mM) to a reaction mixture containing 10 mM linoleic acid (LA), 20% EtOH, and 135 microM dehydroascorbic acid (DHA) as a catalyst suppressed LA peroxidation, but the addition of mannitol (approximately 100 mM), uric acid (100 microM), and catalase (6.5 units) did not. DHA or 2,3...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Bioscience, biotechnology, and biochemistry
دوره 62 7 شماره
صفحات -
تاریخ انتشار 1998