282 PETER REICHARD 



TABLE II 



Incorporation of Glycine-N'^ into the Different Nitrogen Atoms from Uric 



Acid by the Human Male^' 



TABLE III 



Synthesis of Uric Acid by Pigeons after Administration of Ni*H4C1 Together 

 WITH Carbon Isotopic Compounds'^ 



the two groups. However, when glycine-N''*-l-C*^ was administered to- 

 gether with N^^-lableled ammonium chloride, positions 1 plus 3 contained 

 more isotope than positions 7 plus 9 (Table III). This was taken as evi- 

 dence that position 7 in uric acid from pigeons was derived from the nitro- 

 gen of glycine. 



Elwyn and Sprinson'* demonstrated that the N'* of serine was incor- 

 porated into uric acid in pigeons, as might be expected from the well-known 

 transformation of serine into glycine. 



A complete degradation, by which the isotope content of each nitrogen 

 of uric acid could be obtained, was described by Lagerkvist.^° The method 

 is outlined in Fig. 2. Uric acid was methylated to a mixture of 3- and 

 9-methyluric acids by the method of Fischer.^^ By oxidation with KCIO3 

 the 3-methyluric acid was converted to methylalloxan which, on further 

 oxidation with Pb02 and hydrolysis with HCl, gave nitrogen atoms 1 and 

 3 as ammonia and methylamine, respectively. Position 7 of the uric acid 

 was obtained as glycine in a separate procedure by the well-known method 

 of Strecker.^^ 



'0 U. La*gerkvist, Arkiv Kemi 5, 569 (1953). 

 3' E. Fischer, Chem. Zentr. 1897, II, 157. 

 32 A. Strecker, Z. Chem. 4, 215 (1868). 



