Glucosylamine

S. Bayne und W. H. Holms (16) behaupten, daB die o-Isomeren von Tolyl-, Chlorphenyl- und Carboxyphenyl-glucosylamin in schwach saurer Losung weniger leicht als die m- und />-Isomeren die Amadori-Umlagerung erleiden. 

Figure 1.117 Glucosylamine derivatives can be prepared at the reducing end of glycans or other reducing carbohydrates by reaction with ammonium carbonate. The resultant amine derivative can be used to conjugate the carbohydrate with other proteins or molecules without disturbing the cyclic character of the reducing end.

Nach 1. c. 17) zeigt die RG in Athanol ein pH -abhangiges Maximum, das, ahnlich wie bei der Hydrolyse, fiir N-p-Nitrophenyl-glucosylamin in starker sauerem Bereich liegt als fiir N-p-Tolyl-glucosylamin i ). Es konnte wahrscheinlich gemacht werden, daB die Transglycosidierung spezifisch Saure-katalysiert ist. 

Die Halbwertszeiten des Austauschs von N-p-Tolyl-glucosylamin, N-p-Tolyl-4.6-0-benzyliden-glucosylamin,N-p-Tolyl-3.4.5.6-tetrabenzoyl-glucosylamin und Glykolaldehyd-p-toluidid mit p-Toluidin imter-scheiden sich um GroBenordnungen (vgl. Tabelle 1). Nach 1. c. i7) ist der Mechanismus 35 39 - 40 - 41 - -42 - 37 oder 35 39 - -41 - -42 - ... 

From Scheme 2, it may be seen that D-glucosylamine and D-fructo-sylamine are also considered to be intermediates in the formation of heterocyclic compounds. This intermediary formation of 1-amino-1-deoxy-D-fructose and D-glucosylamine from D-glucose and am-... 

The rate constants kr and k2 have values of 20 X 10-3 and 22 X 10-3 min-1, respectively, in 2 M hydrochloric acid at 100°, and the overall rate of decomposition of 2-acetamido-l-N-/3-L-aspartyl-2-deoxy-/3-D-glucosylamine occurs with a rate constant of 42 X 10-3 min-1, that is, a half-life of the order of 17 minutes.92 L-Aspartic acid and ammonia are released at the same rate.92-95... 

An experiment whose results support certain mechanistic views (see Section VI, p. 110) was the ammonolysis of 2,3,4,6-tetra-O-benzoyl-D-glucopyranosylamine,30 which afforded a mixture of D-glucose and D-glucosylamine in 95% yield, and only 1.4% of l,l-bis(benzamido)-l-deoxy-D-glucitol (17) with traces of N-benzoyl-D-glucopyranosylamine. 

For the N-acylaldobiosylamines, this method requires a second oxidation and further reduction, as shown for N-acetyl-6-O-a-D-galactopyranosyl-/3-D-glucosylamine (N-acetyl-/3-meIibiosylamine)49 (54) in the following sequence. 

As we stated previously, glucose forms some, but not all, of the common carbonyl derivatives. The amount of free aldehyde present in solution is so small that it is not surprising that no hydrogen sulfite derivative forms. With amines, the product is not a Schiff s base but a glucosylamine of cyclic structure analogous to the hemiacetal structure of glucose, Equation 20-3. The Schiff s base is likely to be an intermediate that rapidly cyclizes to the glucosylamine ... 

Figure 13. Formation of glucosyl-n-butylamine and glyoxal dialkylimine during the reaction of glucose (0.25 MJ with t-butylamine (1 MJ in ethanol. Key 0, glucosylamine A, imine 9, browning.

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