Glucosylamine hydrolysis

Methylation thus points to A -phenyl-u-glucosylamine s reacting in the cyclic pyranose structure and certainly lends no support for the existence of the acyclic form (VI) which would yield, after methylation and hydrolysis, penta-O-methyl-aWe/iydo-D-glucose. Irvine and his colleagues conducted their methylation experiments under extremely mild condi-... 

A recent paper by Kawashiro, the original of which is not available to the reviewers, gives details of the oxidation of N-m- and N-p-nitrophenyl-D-glucosylamines by periodic acid under the usual conditions. The degree of hydrolysis of the glucosylamines is less than 30 %, and exactly five moles of oxidant are consumed, with the production of the quantity of formic acid which would result from the similar oxidation of glucose. The reaction is given as follows. 

Figure 1.24 Mutarotation and hydrolysis of glycosylamines, illustrated with N-aryl glucosylamines.

A most interesting application having commercial value is the formation of surface-active derivatives by the condensation of hydrophilic sugars with fatty amines. Only Amadori rearrangement gave hydrolysis-resistant compounds, displaying a considerable decrease in the surface tension of water, in contrast to the glucosylamine derivatives. 

Lubineau group showed that the freeze-dried glucosylamine obtained directly from glucose could be opposed to succinic anhydride to give the double nucleophilic addition. After acidic hydrolysis the sugar moiety was linked to a spacer with a carboxylic acid functionality (Scheme 11). ... 

In certain of their reactions, the substances behave as Schiff bases. However, since methylation by the use of methyl iodide and silver oxide and subsequent hydrolysis of the glucosylaniline (glucose anilide) (I) lead to tetra-O-methylglucopyranose (III) 16) the compound probably has a pyranose ring 16). The identical tetra-O-methyl pyranose ether (II) was obtained by methylation of Ar-phenyl-D-glucosylamine (I) by the use of dimethyl sulfate and sodium hydroxide, though only in 25% yield 17a, b). 

The ease of hydrolysis of glycosylamines parallels the base strength of the corresponding amine, with the exception of glucosylamine itself 12, 62). Normal acetic acid was found to be a more effective hydrolyzing agent than 0.5 N hydrochloric acid, whereas the effect of dilute sodium hydroxide... 

A stable enzyme-D-glucose intermediate has been obtained in the hydrolysis of methyl a-D-[ C]glucopyranoside by an a-D-glucosidase from Saccharomyces oviformis Phenol was used to terminate the reaction and to trap the intermediate in a rapid-flow technique. The intermediate appears to be covalently linked, since continuous washing of the denatured protein failed to remove the radiolabel, which was also retained by a tryptic peptide isolated by gel filtration. Treatment of the intermediate with acid released D-[ C]glucose. The radiolabel was not bound when the enzyme was replaced with bovine albumin or when jS-D-glucosylamine (a potent inhibitor of a-D-glucosidase) was added with the enzyme. 

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