L-dehydroascorbic Acid Research Articles

Effect of ascorbic acid and related compounds on the tobacco hornworm, Manduca sexta Johannson (Lepidoptera: Sphingidae)

The effect of L-ascorbic acid (1) and related compounds on the growth of the tobacco hornworm, Manduca sexta Johannson, was determined. The dietary level of 1 necessary for normal development was 0.5 mM. Magnesium 2-O-phosphono-~-ascorbate, sodium 6-O-myristoyl-~-ascorbate, and L-dehydroascorbic acid were equally potent as 1. In contrast, analogues such as D-ascorbic acid, 6-bromo-6-deoxy-~-ascorbic acid, and D-isoascorbic acid were approximately one-half, one-fifth, and one-tenth as effective. Potassium 2-O-sulfato-~-ascorbate, L-isoascorbic acid, reductic acid, L-gluconic acid y-lactone, piperidinohexose reductone, dimethylaminohexose reductone, a-tocopherol acetate, p-hydroquinone, pyrocatechol, 2,3-dihydroxy-1,4-dithiobutane, sodium dithionite, and ferrous sulfate were at most only one-twentieth as active as 1.

Biochemical studies on L-ascorbic acid in aquatic animals. VII. Reduction of dehydro-L-ascorbic acid in fishes.

The reduction of dehydro-L-ascorbic acid (DAsA) to L-ascorbic acid (AsA) was investigated in carp by means of radioactive tracer techniques. Six hours after intraperitoneal administration of DAsA-1-14C, 9.9% was recovered as“total AsA-14C”of which 96% was in the reduced form in the hepatopancreas. The reduction of DAsA-1-14C was also observed in other tissues such as kidney, eye, brain and blood. The reduction of DAsA was assayed in vitro by using the crude extract of carp hepatopancreas. The reduction of DAsA by GSH increased remarkably in the presence of crude extract as compared to nonenzymatic reduction. Heating the extract for 5 min at 100°C resulted in the complete loss of its activity. These results indicate the presence of DAsA-reductase in carp hepatopancreas. The enzyme in carp was found mainly in the hepatopancreas and kidney, and showed the same level of activity as the rat liver enzyme. The enzyme activity was also detected in all of the fishes so far tested.

Volatile degradation products of l-dehydroascorbic acid.

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. Fifteen products were identified, among which 12 had not yet been reported as degradation products of L-dehydroascorbic acid. Concentrations of 5 main degradation products, i.e. 3-hydroxy-2-pyrone, 2-furancarboxylic acid, 2-furaldehyde, acetic acid and 2-acetylfuran depended on the pH values and temperature; the presence of oxygen had no pronounced effect.

Formation of 3-keto-4-deoxypentosone and 3-hydroxy-2-pyrone by the degradation of dehydro-l-ascorbic acid.

A crystalline phenylhydrazone was obtained when a heated solution of dehydro-l-ascorbic acid (DHA) was treated with phenylhydrazine-HCl. Its molecular formula was C17H18N4O2, and the structure was determined to be 1,2-bis(phenylhydrazone) of 3-keto-4-deoxypentosone, a new tricarbonyl compound which was considered to be one of the possible intermediates of the browning reaction of DHA. 3-Hydroxy-2-pyrone was also isolated from the ether extract of the heated DHA solution as a main aroma compound produced from DHA. Possible formation mechanisms of these compounds were discussed.

The Release of L-Ascorbic acid and L-Dehydroascorbic acid from Human Erythrocyte

The Release of L-Ascorbic acid and L-Dehydroascorbic acid from Human Erythrocyte

L-Dehydroascorbic acid Incorporation into Human Erythrocyte and in vivo and in vitro Transformation into L-2,3-Diketogulonic acid

L-Dehydroascorbic acid Incorporation into Human Erythrocyte and in vivo and in vitro Transformation into L-2,3-Diketogulonic acid

果実•そ菜のアスコルビン酸に関する生理化学的研究 (第1報)

This paper describes the changes of ascorbic acid content in okuras during maturation, storage period and at different harvest time. The results obtained were as follows:1) L-Ascorbic acid and L-dehydro ascorbic acid content in okuras declined during maturation and total ascorbic acid content at harvest time was about 30mg/100gf. wt.2) L-Ascorbic acid content in okuras by normal culture (open culture) was contained more than that by off-season culture (growing in plastic green house), and the okuras harvested in July and August especially showed a higher content.3) The storage at 12°C was better condition on the point of freshness and the retention of ascorbic acid in okuras during storage. L-Ascorbic acid rapidly decreased with the advance of chilling injury at 1°C storage.4) On the purpose of the prevention of chilling injury and the retention of ascorbic acid, effects of controlled atmosphere storage(CO2-3, 10, 20%: O2-3%) were investigated at 1°C and 12°C. As a result, there was not a significant difference between 1°C-CA storage and 1°C-air storage about the retention of ascorbic acid content and the keeping of freshness.On the other hand, 12°C-CA storage resulted in a lower ascorbic acid content as campared with 12°C-air storage, but the former was superior to the latter in the keeping freshness.

Red Pigment Produced by the Reaction of Dehydro-l-ascorbic Acid with α-Amino Acid

At the initial stage of the browning reaction of dehydro-l-ascorbic acid (DHA) with α-amino acid, a kind of red pigment was produced. The pigment was isolated as very hygroscopic red powder from non-aqueous reaction system, and its characterization was made. It was revealed that it had the same structure with that of the red pigment produced by the oxidation of l-scorbamic acid, an intermediate amino-reductone expected to be produced by Strecker degradation. Formation mechanism of the pigment which was considered to be an intermediate of browning reaction of DHA with α-amino acid was also discussed.

Red Pigment Produced by the Reaction of Dehydro-L-ascorbic Acid with α-Amino Acid

At the initial stage of the browning reaction of dehydro-l-ascorbic acid (DHA) with α-amino acid, a kind of red pigment was produced. The pigment was isolated as very hygroscopic red powder from non-aqueous reaction system, and its characterization was made. It was revealed that it had the same structure with that of the red pigment produced by the oxidation of l-scorbamic acid, an intermediate amino-reductone expected to be produced by Strecker degradation. Formation mechanism of the pigment which was considered to be an intermediate of browning reaction of DHA with α-amino acid was also discussed.

魚肉のゲル形成におよぼすアスコルビン酸の影響

The addition of L-ascorbic acid (AsA) and dehydro-L-ascorbic acid (DAsA), after adjustment to pH 6.4 and 4.3 with sodium hydroxide respectively, to Alaska pollack brayed meat caused increase in the strength of the gel. Both AsA and DAsA had improving action on the gel strength, but DAsA was more potent than AsA. About 80% of added AsA was recovered as the reduced form in the gel when AsA was added to the brayed meat. On the other hand, about 20% of added DAsA was reduced to AsA when DAsA was added to the meat. These results suggest that the improving action of AsA in the gel formation may be due to the oxidation of sulfhydryl groups in fish proteins by DAsA. When AsA was heated with actomyosin in solution at 80°C for 20 minutes, AsA was almost completely recovered as the reduced form. On the other hand, when DAsA was heated with actomyosin at 80°C, some of it was reduced rapidly to AsA by the reaction with actomyosin during the first 5 minutes. These results suggest that DAsA may oxidize sulfhydryl groups in the actomyosin molecule.

On the behaviour of L-dehydroascorbic acid in aqueous solutions

On the behaviour of L-dehydroascorbic acid in aqueous solutions

Utilization of dehydroascorbic acid and some related compounds by the aphid Myzus persicae feeding on an improved diet

Modifications are described in the formulation of an artificial diet for rearing Myzus persicae. Using this aphid species and the dietary improvements, we determined the relative growth of larvae, derived from ascorbic acid-deprived apterous mothers, on diets containing ascorbic acid or related compounds at various concentrations. l-Dehydroascorbic acid (the oxidized form of l-ascorbic acid) is utilizable, but only about 50 per cent as efficiently as equivalent amounts of l-ascorbic acid. d-Araboascorbic acid (an epimer of l-ascorbic acid about C 5) is almost equivalent to l-ascorbic acid. d-Glucurono-γ-lactone and l-gulono-γ-lactone (intermediates in the biosynthesis of ascorbic acid in some mammals) are not utilized to any extent, nor was reduced glutathione (an unrelated reducing substance). The results are discussed in relation to the enzyme specificity and biosynthetic capabilities of other insects and animals.

Decomposition of Dehydro-l-ascorbic Acid and Dehydro-erythorbic Acid

Decomposition of dehydro-l-ascorbic acid (DAA) and dehydro-erythorbic acid (DEA) in buffer solution was accelerated by increasinig pH, and by elevating temperature, especially at high pH, while it was little affected by their concentrations, the presence of 2×10-4M, Ca++, Cu++, and Cr+++, and aeration. At 30 and 35°C and pH 7.0, DEA decomposed more rapidly than DAA.

REDUCTION OF DEHYDROASORBIC ACID BY ANIMAL TISSUES.

IT has long been known that an enzyme catalysing the reduction of dehydro-L-ascorbic acid (DHA) by glutathione to ascorbic acid occurs in plant tissues1–3. It can also be shown that DHA is in part reduced to ascorbic acid by animal tissues, although until recently no clear evidence was available to suggest that this is an enzymatic reaction. Recently, however, it has become clear that the reduction of DHA by haemolysates of human erythrocytes occurs at a rate greater than can be accounted for in terms of a purely chemical reduction by glutathione4,5.

Polarographic Investigations of Vitamin C. III. Reduction Waves of the Condensation Products of Dehydro-l-ascorbic Acid and its Related Compounds with o-Phenylenediamine. Application to the Simultaneous Determination of l-Ascorbic Acid, Dehydro-l-ascorbic Acid and their Related Compounds

Abstract The polarographic behavior of dehydro-l-ascorbic acid (DAA), dehydroreductic acid (DRA), alloxan, mesoxalaldehyde (MOA) and 2,3-diketogulonic acid (DGA) in acid buffer solutions containing o-phenylenediamine(OPD), has been investigated. DAA shows three diffusion controlled reduction waves, whose half-wave potentials(E1⁄2) at pH 3.60 are −0.26, −0.44 and −0.67 V. (vs. N. C. E.), respectively. The limiting currents of the three waves depend on the time after the addition of OPD into the electrolytic solution, the concentration of OPD. pH and the temperature. When the electrolytic solution contains both AA and DAA, the oxidation wave of l-ascorbic acid (AA) can be obtained independently of the three waves for DAA in one polarogram. DGA shows two reduction waves whose E1⁄2 at pH 3.44 are −0.27 and −0.40 V., respectively. The E1⁄2 of the first wave is very close to that of the first wave for DAA and the second wave seems to be identical with the second wave for DAA, but the velocities of the condensation reactions of DGA with OPD are much slower than those of DAA with OPD. Alloxan and DRA show single well defined reduction waves, whose E1⁄2 at pH 3.60 are −0.32 and −0.19 V., respectively. The oxidation wave of reductic acid (RA) can be obtained with the reduction wave for DRA in one polarogram, while the oxidation wave of dialuric acid decreases very fast when alloxan and OPD are added into the electrolytic solution even after the careful removal of the atmospheric oxygen. MOA shows a somewhat complicated behavior. In acid pH, the waves are not well defined and are considerably smaller than those of the above substances of the same concentration. Discussions are made on the structures of the condensation products corresponding to their reduction waves. Since the linear relationship between the limiting current and the concentration has been obtained, for DAA (the 3rd wave), DRA and alloxan, these polarographic phenomena have been applied to the simultaneous determination of AA and DAA, and to that of RA and DRA and further to that of AA and RA. The method is also applicable to the determination of alloxan, but not to those of MOA (or TR) and DGA, none of which, however, seriously interfere with the determination of DAA (or AA) by means of this polarographic OPD method.

Total Ascorbic Acid in Aqueous Humor and Serum in Indian Patients With and Without Cataract

The total ascorbic acid concentration in aqueous comprising two components, the reduced form asl-ascorbic acid, and the oxidised product, as dehydrol-ascorbic acid,3although very variable, is very much higher than in blood plasma. In various animals, including man, the concentration ratio approximates 6-8:1.* Moreover, recently, it has been found that the concentration of ascorbic acid in the aqueous humor varies approximately as the concentration in the serum, regardless of whether or not the lens is cataractous, the subjects of this investigation being normal patients, aphakic patients, and patients whose lenses were sufficiently opaque to warrant extraction.7The present paper deals with a comparative study of total ascorbic acid in aqueous and serum of Indian patients of three categories: (a) with normal lens, (b) with different types of cataract, (c) with lenses extracted previously. Selection of Patients The selected subjects were first subjected to a thorough examination