CHEMICAL BASIS OF THE ANIMAL BODY. 12G9 



Weielel's reaction or the reaction with nitric acid and caustic 

 soda so characteristic of the other xanthine bases. It gives no 

 green coloration with caustic soda and chloride of lime such 



Fig. 222. Hypoxanthine-hydrochloride, C5H4N4O . HC1. (Kilhne.) 



as xanthine does, but after treatment with hydrochloric acid 

 and zinc, it yields a ruby-red coloration on the addition of an 

 excess of caustic soda. In this reaction it resembles adenine. 



6. Adenine. C 5 H 5 N 5 . (Imido-hypoxan thine.) 

 Nil — CH 



CH C — NH 



II I 



N — C= N 



)C = NH. 



This base was first obtained during the treatment of pan- 

 creatic tissue for the preparation of hypoxanthine. It is a 

 product of the decomposition of the nucleins and may therefore 

 be prepared from any tissue rich in nuclei such as the spleen, 

 thymus and lymphatic glands. It is present in considerable 

 amount in the leaves of tea and is found in the urine of leukhse- 

 It bears the same relationship to hypoxanthine that 



mi a. 



guanine does to xanthine, and can similarly be converted into 

 hypoxanthine by the action of nitrous acid. 



When pure it crystallizes in needles from aqueous solutions. 

 Is soluble in 1086 parts of cold water, readily in hot water, 

 insoluble in ether, slightly soluble in hot alcohol. Yields 

 crystalline compounds with acids, also with some salts. The 

 compound with nitrate of silver is soluble in hot nitric acid 

 (sp. gr. 1*1), and is thus separable, together with hypoxan- 

 thine, from xanthine. It also yields a readily crystalline com- 

 pound with picric acid, which is very insoluble in cold water 

 (1 in 3500) and may be used for its quantitative separation 

 from solutions. It does not give the ordinary reactions char- 



