Studies on Choline Derivatives. II

Glutamylcholine. (2)

Abstract

Reaction of N-carbobenzoxyglutamic anhydride and choline chloride yielded carbo-benzoxyglutamylcholine whose reduction to glutamylcholine and its ammoniac decomposition gave l-isoglutamine (I) and l-2-ketopyrrolidine-5-carboxylic acid (II). The crystals which precipitate out on reduction (assumed as a mixture of glutamyl-γ-choline (V) and glutamic acid, by the paper partition chromatography), and hydrazine yielded l-glutamic-γ-hydrazide (III). The ammoniac decomposition of the intermediate, N-carbobenzoxyglutamylcholine, furnished N-carbobenzoxy-l-isoglutamine (VI) whose mother liquor gave l-glutamine (VII) on reduction. Hydrolysis of glutamylcholine with hydrochloric acid yielded l-glutamic acid from which it was seen that no racemization took place during this reaction. From foregoing experimental results, the glutamylcholine obtained by the afore-mentioned method was proved to a mixture of l-glutamyl-α-choline (IV) and l-glutamyl-γ-choline.