This reaction can be formulated as in Scheme 2.1.
It should be noted that each of the steps in Scheme 2.1 is reversible. The amine
can be a protein, and it has been shown that insulin will react with glucose at a sig- nificant rate even at room temperature.
There is no fundamental reason why the glycosylamine should not act as the amine for a further molecule of aldose, thus giving a diglycosylamine.
N-Substituted glycosylamines on mild heating give fluorescent nitrogenous com- pounds, which can rapidly react with glycine to give melanoidins. It seems therefore that a reaction of type G can, under certain circumstances, short-circuit Reaction B, etc. (cf. Reaction H).
Lysine locked up as ε-glycosylamine appears to be nutritionally available.7