Araboascorbic Acid Research Articles

An Efficient Petasis Boronic–Mannich Reaction of Chiral Lactol Derivatives Prepared from d-Araboascorbic Acid

Optically active polyhydroxy trans-1,2-amino alcohols were efficiently synthesized in good to excellent yields by the Petasis­ boronic–Mannich reaction of an amine, an organoboronic acid, and a chiral lactol, which was prepared from d -araboascorbic acid or its diastereomer. Further transformations of the resulting Petasis products were investigated in detail to obtain chiral building blocks containing three continuous stereogenic centers.

Low-frequency Raman scattering of aqueous solutions of L-xyloascorbic acid and D-araboascorbic acid

Depolarized low-frequency Raman spectra of aqueous solutions of L-xyloascorbic acid and its epimer D-araboascorbic acid have been investigated as a function of concentration at 30 °C. The influence of fluorescence in the low-frequency Raman spectral intensity of D-araboascorbic acid aqueous solution was removed by the background correction. The reduced χ″(ν̄) spectrum, which corresponds to the imaginary part of the dynamical susceptibility due to the dynamical structure of water in aqueous solutions, was analyzed with the superposition of one Cole–Cole type relaxation mode and two damped harmonic oscillator modes. The effect of L-xyloascorbic acid on the dynamical structure of water is less than that of D-araboascorbic acid.

Evidence for an action of araboascorbic acid on dopaminergic pathways of the corpus striatum

The relative decrease in the 2 h accumulation of administered [ 3H]-spiperone (SPI)-2 μCi/kg, 0.0004 mg/kg, SC-in mouse corpus striatum, a brain area with a high dopaminergic input (specific plus nonspecific dopamine receptor ligand binding) and the cerebellum, a brain area with little, if any, dopaminergic input (an index of nonspecific dopamine receptor ligand binding) were used to compare the influence of araboascorbic acid (AraA) with ascorbic acid (AsA) on the dopamine receptor. The abilities of these compounds to potentiate haloperidolinduced catalepsy were also investigated. Pretreatment for 30 min with AraA (1000 or 2000 mg/kg, IP) produced the same dose-dependent decrease in SPI accumulation in corpus striatum as observed with AsA. Accumulation in cerebellum was unaffected by either agent. Furthermore, as previously shown for AsA in rats and monkeys, AsA (1000 mg/kg) potentiated the cataleptogenic effect of haloperidol (0.2 mg/kg, SC). AraA was at least as effective as AsA in potentiating catalepsy produced by the neuroleptic. Thus, it would appear that AraA influenced the dopamine receptor in a manner not unlike that already shown for AsA. Because both agents have almost identical redox potentials but divergent antiscorbutic activities, their reductive properties might be more pertinent to the observed effects than their antiscorbutic properties.

Study on the hydration structure of L-xylo and D-arabo ascorbic acid solutions by time domain reflectometry

The hydration structure of L-xylo and D-arabo ascorbic acids in aqueous solutions were investigated by a dielectric relaxation measurement over a wide frequency range from 10 MHz to 10 GHz from a standpoint on the difference of biological activity at 25 °C. In order to clarify the hydration structure the concentration dependence of dielectric relaxation was investigated not only in aqueous solution but in water–ethanol mixtures. Two kinds of dielectric relaxation processes were observed in each isomerism solution. The low frequency process is assigned to cooperative motions of ascorbic acid molecules and hydrated water. The high frequency process is assigned to reorientational motions of bulk water. From the results of the dehydration process out of the ascorbic acid surface by ethanol it is concluded that the amount of hydrated water of the L-xylo ascorbic acid is more than that of the D-arabo ascorbic acid.

Synthesis of optically active leukotriene (SRS-A) intermediates

In an approach to SRS-A and analogues thereof, the key (5 S , 6 S )-epoxy alcohol 9 and its 6-epimer 18 were prepared starting from D -araboascorbic acid and L -diethyl tartrate, respectively.

Inhibition of reproduction of Xyleborus ferrugineus by ascorbic acid and related chemicals

Effects of various dietary chemicals on the reproduction of the ambrosia beetle, Xyleborus ferrugineus were studied. Ascorbic acid, araboascorbic acid, dehydroascorbic acid, hydroquinone, catechol, cysteine, and α-tocopherol each inhibited progeny production by virgin females. Detailed studies of the effects of ascorbic acid showed that it inhibited progeny production by causing a nutritionally detrimental non-enzymic browning of the dietary casein. Amino acid analyses of such browned and unbrowned casein, after in vitro digestion with pepsin and pancreatin, showed that lesser amounts of certain amino acids were released from the browned material. Effects of the non-enzymic browning were overcome by increasing the casein component of the diet. It was further concluded that araboascorbic acid, dehydroascorbic acid, hydroquinone, and catechol probably inhibit reproduction of X. ferrugineus by the same mechanism as ascorbic acid. No explanation of the inhibitory action of α-tocopherol on X. ferrugineus is offered.

Biosynthesis of stizolobinic acid and stizolobic acid in higher plants. An enzyme system(s) catalyzing the conversion of dihydroxyphenylalanine into stizolobinic acid and stizolobic acid from etiolated seedlings of Stizolobium hassjoo.

It was demonstrated that an enzyme system(s) extracted from etiolated seedlings of Stizolobium hassjoo catalyzed the conversion of L-dihydroxyphenylalanine into stizolobinic acid, alpha-amino-6-carboxy-2-oxo-2H-pyran-3-propionic acid, and stizolobic acid, alpha-amino-6-carboxy-2-oxo-2H-pyran-4-propionic acid, in the presence of NADP+ or NAD+ under aerobic conditions. Enzymically synthesized radioactive stizolobinic acid and stizolobic acid isolated from the reaction mixtures were purified and confirmed to have constant specific radioactivities by cocrystallization with authentic samples. Maximal activity of the enzyme preparation was obtained by using an insoluble polyphenol adsorbent (Polyclar AT) and a reducing agent (araboascorbic acid) in the extraction medium and by subsequent fractionation of the extract with ammonium sulfate followed by Sephadex G-25 gel filtration. Catalytic activity of the enzyme preparation was more unstable under aerobic condition than anaerobic. Attempts to stabilise the enzyme activity were made by the use of many substances which are known to stabilise other enzymes or expected to arrest the inactivation. Evidence is provided in this paper that the previously proposed biosynthetic pathways of stizolobinic acid and stizolobic acid from dihydroxyphenylalanine proceeded in the cell-free system from etiolated seedlings of S. hassjoo.

Production of 3, 4-Dihydroxyphenyl-L-alanine (L-DOPA) and Its Derivatives by Vibrio tyrosinaticus

Six strains of bacteria belonging to Vibrio and Pseudomonas were selected as good producers of L-DOPA from L-tyrosine out of various bacteria. The condition for the formation of L-DOPA by Vibrio tyrosinaticus ATCC 19378 was examined and the following results were obtained. (1) Intermittent addition of L-tyrosine in small portions gave higher titer of L-DOPA than single addition of L-tyrosine. (2) Higher amount of L-DOPA was produced in stationary phase of growth than in logarithmic phase. (3) Addition of antioxidant, chelating agent or reductant such as L-ascorbic acid, araboascorbic acid, hydrazine, citric acid and 5-ketofructose increased the amount of L-DOPA formed. (4) L-Tyrosine derivatives such as N-acetyl-L-tyrosine amide, N-acetyl-L-tyrosine, L-tyrosine amide, L-tyrosine methyl ester and L-tyrosine benzyl ester were converted to the corresponding L-DOPA derivatives. In the selected condition about 4mg/ml of L-DOPA was produced from 4.3mg/ml of L-tyrosine.

Studies on the decomposition of L-ascorbic acid in the coexistence of D-araboascorbic acid. II. On the anaerobic decomposition of L-ascorbic acid in the coexistence of D-araboascorbic acid

Anaerobic decomposition of L-ascorbic acid in the presence of D-araboascorbic acid in aqueous solution was studied. Separation and determination of L-ascorbic acid and D-araboascorbic acid in their mixed aqueous solution were carried out by gas-liquid chromato-graphy. Anaerobic decomposition of L-ascorbic acid alone and D-araboascorbic acid alone was examined at various temperatures (40°, 50°, 65°) and pH values (pH 1.0-6.0). The pH-rate profile of the two compounds clearly showed a maximum at pH=pK1 and the optimum pH for the stability was found to be pH 6.0. The shape of the pH-rate profile of L-ascorbic acid varied with temperature, but that of D-araboascorbic acid varied little with temperature. The present experimental data on anaerobic decomposition of L-ascorbic acid at 40°, 50°, and 65° were in good agreement with the theoretical values calculated from the equation proposed by Higuchi. From kinetics, it seemed reasonable to assume, also in the case of D-araboascorbic acid, the formation of a complex between undissociated araboascorbic acid and monohydrogen araboascorbate. The decomposition of L-ascorbic acid in the presence of D-araboascorbic acid was faster than that of L-ascorbic acid alone. The stabilizing effect of D-araboascorbic acid for the decomposition of L-ascorbic acid was not observed in the anaerobic aqueous solution.

Carbohydrate oxidase, a novel enzyme from polyporus obtusus: II. Specificity and characterization of reaction products

1. 1. Carbohydrate oxidase, an enzyme obtained from the mycelium of the Basidiomycete Polyporus obtusus, has been shown to catalyze the oxidation of several carbohydrates at the second carbon atom to yield 2-keto products. The reactions catalyzed are as follows: 1.1. a. d-glucopyranose + O 2 → d-glucosone + H 2O 2 1.2. b. d-xylopyranose + O 2 → d-xylosone + H 2O 2 1.3. c. l-sorbose + O 2 → 5-keto- d-fructose + H 2O 2 1.4. d. δ- d-gluconolactone + O 2 → 2-keto- d-gluconic acid + d-araboascorbic acid + H 2O 2 2. 2. Other carbohydrates were tested and found not to be substrates. The structural requirements for substrate reactivity were studied. 3. 3. The oxidation of δ-gluconolactone to araboascorbic acid was shown to be inhibited by d-glucose, d-xylose and l-sorbose. 4. 4. The specificity of carbohydrate oxidase was compared with that of enzymes reported to occur in other microorganisms.

L-Ascorbic acid degradation by bacteria. VI. Metabolic pathway of L-ascorbic acid through D-arabo-ascorbic acid.

1. D-Gluconic acid and D-ribose are degraded well accompanied with phosphorylation by both adapted and inadapted cells for ascorbic acid, whereas other pentoses, e.g., DL-xylose and DL-arabinose, are not matabolized.2. It was assumed by successive adaptation that AsA is partially degraded through araboascorbic acid through the Warburg-Dickens-Cohen pathway. Araboascorbic acid is also assumed to proceed through the above pathway.

L-Ascorbic acid degradation by bacteria. VII. Metabolic pathway through dehydroascorbic acid.

1. The unadapted cells are not capable of adapting for ascorbic acid, even if they are in contact with ascorbid acid for a long time, but they can adapt rapidly in the presence of a small amount of glucose and of casein hydrolysate.2. Ascoraic acid-adapted cells degrade araboascorbic acid and glucoascorbic acid besides AsA, but fail to degrade other reductones, e.g., reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.3. The optimal pH of the ascorbic acid-oxidase in the unadapted cells is 5.0 and the optimal substrate concentration is 800μM.4. The ascorbic acid-oxidase is inactive for the reductones other than ascorbic acid i.e., araboascorbic acid, glucoascorbic acid, reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.

L-Ascorbic acid degradation by bacteria. V. Adaptability of L-ascorbic acid-degrading bacterium.

1. The unadapted cells are not capable of adapting for ascorbic acid, even if they are in contact with ascorbid acid for a long time, but they can adapt rapidly in the presence of a small amount of glucose and of casein hydrolysate.2. Ascoraic acid-adapted cells degrade araboascorbic acid and glucoascorbic acid besides AsA, but fail to degrade other reductones, e.g., reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.3. The optimal pH of the ascorbic acid-oxidase in the unadapted cells is 5.0 and the optimal substrate concentration is 800μM.4. The ascorbic acid-oxidase is inactive for the reductones other than ascorbic acid i.e., araboascorbic acid, glucoascorbic acid, reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.

L-ascorbic acid degradation by bacteria. I. Mechanism of L-ascorbic acid degradation.

1. The unadapted cells are not capable of adapting for ascorbic acid, even if they are in contact with ascorbid acid for a long time, but they can adapt rapidly in the presence of a small amount of glucose and of casein hydrolysate.2. Ascoraic acid-adapted cells degrade araboascorbic acid and glucoascorbic acid besides AsA, but fail to degrade other reductones, e.g., reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.3. The optimal pH of the ascorbic acid-oxidase in the unadapted cells is 5.0 and the optimal substrate concentration is 800μM.4. The ascorbic acid-oxidase is inactive for the reductones other than ascorbic acid i.e., araboascorbic acid, glucoascorbic acid, reductic acid, dihydroxymaleic acid and 5-methyl-3, 4-dihydroxytetrone.

50. Methyl ethers of arabo-ascorbic acid and their isomerism

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