D-Glucoascorbic acid

This method, utilized simultaneously by Reichstein2 and by Haworth and coworkers3 in the first synthesis of d- or L-ascorbic acid, can be illustrated in detail by reference to the preparation of D-glucoascorbic acid (XV).3... 

D-Glucosone (XII), prepared from D-glucose phenylosazone (XI) by the action of concentrated hydrochloric acid, is treated in aqueous solution with potassium cyanide. The imino-D-glucoascorbic acid (XIV) which readily separates shows many of the properties of ascorbic acid. Thus it shows a strong selective absorption band in the ultra-... 

When the imino compound XIV is heated with dilute hydrochloric acid, hydrolysis of the imino group takes place and there is formed ammonium chloride and D-glucoascorbic acid (XV). The latter displays all the chemical properties of L-ascorbic acid. 

Treatment of D-glucoascorbic acid (XV) with diazomethane gives a 2,3-dimethyl derivative (LXXIX) and this upon repeated treatment with silver oxide and methyl iodide yields 2,3,5,6,7-pentamethyl-D-glucoascorbic acid (LXXX). Ozonization of the latter followed by hydrolysis gives oxalic acid and 3,4,5-trimethyI-D-arabonic acid (LXXXI). This acid was shown to possess a free hydroxyl group at C2 by reason of the fact that the amide of LXXXI gives a positive Weerman reaction for a-hydroxy amides, i.e., when the amide is treated with sodium hypochlorite, sodium isocyanate is produced, the latter being identified by... 

Lactosone was first prepared by the hydrochloric acid decomposition of the phenylosazone,1 although it had been noted that, in acid solutions, lactose phenylosazone forms an anhydride.197 Since its discovery,17 the benzaldehyde method has usually been employed,6-10-28 because it avoids the risks of osone hydrolysis and of alteration to the osazone. Lactosone is hydrolyzed by hot, dilute, mineral acid to D-glucosone and D-galactose.1-6 It reacts with cyanide to form an analog of iminoascorbic acid which, on acid treatment, is converted into a mixture of D-glucoascorbic acid and D-galactose.10... 

Pentamethyl-D-glucoascorbic acid on ozonolysis and hydrolysis gives 3,4,5-trimethyl-D-arabonic acid.88 The ester and the amide are also described, the constitution of the latter following from the fact that it gave a positive Weerman test. 

D-glucoascorbic acid (0.05-0.3%) in diet produced deformed spermatophores... 

Isoascorbic acid, D-glucoascorbic acid/ and several other compounds totally unrelated to L-ascorbic acid have the same activity as ascorbic acid on tyrosine oxidation in vitro. Since D-glucoascorbic acid has no antiscorbutic activity and isoascorbic acid has only a fraction of the antiscorbutic activity of ascorbic acid, it has been suggested that the antiscorbutic activity of ascorbic acid is distinct from its role in maintaining normal tyrosine metabolism. However, the differences observed may be explained by the differences in retention and distribution of these compounds in the body. ... 

The apparent ascorbic acid requirement of the trichomonads appears to be non-specific, however, and the compound functions not as a vitamin but as a reducing agent. This is in contrast to the situation in the trypanosomids (see above). Thus D-isoascorbic acid, D-glucoascorbic acid, and other reducing agents were as active in promoting the growth of the trichomonads as was ascorbic acid itself. 

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