General Chemical Properties of y-Glutamyl Derivatives

Degradation and General Chemical Properties of y-Glutamyl Derivatives 

In strong base glutamine is hydrolyzed easily to give ammonia (300), but base hydrolysis has not been studied as thoroughly as acid hydrolysis [cf. (78), p. 1933]. 

the presence of the non-acylated a-amino group is necessary for the reaction, as demonstrated by the stability of N -chloroacetyl-glutamine (70). The reaction is catalyzed by both acid and base (70) and has been shown to follow pseudo-first-order kinetics between pH 3 and 6 (/). 

Glutathione readily undergoes a similar degradation. Thus it has been shown that oxidized glutathione (5) is transformed on boiling with water to 5-oxoproline and the diketopiperazine anhydrodiglycyl-cysteine (6) (103), and that reduced glutathione (7) is transformed 

N -(y-Glutamyl)lysine likewise yields 5-oxoproline and lysine when heated in H2O or glacial acetic acid, whereas N -(a-glutamyl)lysine yielded the corresponding 5-oxoproline derivative. By treatment with acid the latter could be opened to give N -(a-glutamyl)lysine again (168). 

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Degradation and General Chemical Properties of y-Glutamyl Derivatives. . 224... 

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