Derivatives of N-glycylglucosylamine have been prepared in preliminary experiments directed towards the synthesis of " glycineamide ribotide " (I) and its formyl derivative (11) , two early nucleotide precursors. Tetra-Oacetyl-P-D-glucopyranosylamine (111) with chloroacetyl chloride gave the N-chloroacetyl derivative (V) . Replacement of the chloro-by an aminogroup and simultaneous deacetylation, by means of ammonia, gave N-glycylfl-D-glucopyranosylamine (VI) which was readily converted into its N-forpyl derivative. An alternative synthesis of the glycyl compounds involves reaction between the amino-sugar and benzyloxycarbonylglycyl chloride or benzyloxycarbonylglycyl ethyl carbonate, followed by removal of protecting groups, IT has been shown by J. M. Buchanan and his collaborators that the uric acid excreted by pigeons is built up from simple substances supplied in the diet. By feeding isotopically labelled compounds and studying the distribution of isotopes in the uric acid formed, it was found that the carbon and nitrogen atoms of the carboxyl, methylene, and aminogroups of glycine were incorporated as a unit into positions 4, 5, and 7 respectively in uric acid. The carbon at positions 2 and 8 originates from formate, and that at position 6 from carbon dioxide.14 The origin of the nitrogen at positions 1, 3, and 9 was not determined conclusively but recent evidence suggests that the atoms at positions 3 and 9 come from the amide-nitrogen of glutamine and that at position 1 from the a-amino-group of aspartic or glutamic acid.5In pigeon-liver extracts hypoxanthine (6-hydroxypurine) is formed rather than uric acid and it is generally considered that this is the normal precursor of uric acid produced by the living bird. It was shown by Greenberg that the hypoxanthine arose through enzymic hydrolysis of inosinic acid and that the ribose-5 phosphate residue in this compound was attached at quite an early stage in its biosynthesis.s-8 Although all the stages in the H formation of inosinic acid from ribose-5 phosphate, glycine, etc., have not yet been clarified, several of the intermediates have now been isolated or detected chr~matographically.~~ ' 2Recent evidence suggests that N-glycy~-~-ribofuranosy~amine-5 phosphate (" glycineamide ribotide ") (I) is formed from glycine, glutamine, and 5-phosphorylribose-1 pyrophosphate (PRPP) in the presence of enzymes in pigeon liver.lO.ll The stages involved in this synthesis are not yet settled, but it appears that glutamine contributes its amide-nitrogen to form the amide-nitrogen of glycineamide ribotide, and that adenosine

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1. When [1:2 -14C2]ethanolamine, serine, L-[3H]serine or D-[3H]serine was administered orally to earthworms, serine ethanolamine phosphodiester and lombricine were found to be radioactively labelled.2. For each of the precursors the specific radioactivity of serine ethanolamine phosphodiester was greater than that of lombricine in both muscle and gut tissue.3. The specific radioactivity of serine ethanolamine phosphodiester and lombricine was greater in gut than in muscle. With [1:2-4C2]ethanolamine most of the radioactivity of muscle lombricine was in the guanidinoethanol portion of the molecule, whereas with DL-[3-L4C]serine most of the radioactivity was in the serine portion.5. When L-[amidino-14C]arginine was given, there was negligible radioactivity in serine ethanolamine phosphodiester and considerable radioactivity in lombricine, almost all of which was in the guanidinoethanol portion of the molecule.6. These findings suggest that serine ethanolamine phosphodiester is the precursor of lombricine in the earthworm and that the amidino group is derived from arginine by the transamidinasecatalysed transfer of the amidino group to serine ethanolamine phosphodiester.We are indebted to Dr D. I. Magrath and Mrs I. M. Beatty for a sample of synthetic SEP, to Dr R. Norris for advice about the earthworms and to Mr P. Allen for technical assistance. 126, 446. amino acid oxidase were purchased from * Salters' Student. RIBITOL TEICHOIC ACID FROM BACILLUS SUBTILIS L. Light and Co. Ltd., Colnbrook, Bucks. B. &subtilis was grown from a culture provided by Dr M. R. J. Salton.

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A rapid, efficient means of resolving mixtures of isomeric glycosides is described. The method involves chromatography on a strongly basic anionexchange resin in the hydroxide form. It has been employed for the separation of furanosides from pyranosides, a-a-mixtures of anomers, and a mixture of the methyl a-glycosides of two different hexoses.