OXYDIAMINO-ACIDS. 161 



CyH n NsO-t-H 3 O. In the first case this base would appear to be a homologue of 

 creatine, C 4 H 9 N 3 2 , and in the other case a homologue of creatinine, C 4 H 7 N 3 O, 

 and this is the reason why this body is called lysatine as well as lysatinine. It 

 is still a question whether lysatine is a chemical individual or, as HEDIN suggests, 

 only a mixture of lysine and arginine. 1 



In the preparation of the above bases we can first precipitate all the 

 bases by phosphotungstic acid, when the monamino-acids remain in solu- 

 tion. The precipitate is then decomposed in boiling water by barium 

 hydroxide and the bases obtained as silver compounds from this filtrate. In 

 regard to further details we must refer to the works of DRECHSEL and 

 HEDIN already cited. KOSSEL and KUTSCHER and recently WINTERSTEIN 2 

 have suggested a method of separating histidine and arginine as silver 

 compounds from lysine, and KOSSEL and PATTEN have proposed a method 

 of separating histidine from arginine by means of mercuric sulphate. 



We give below a tabulation of the amounts of the three hexone bases 

 found in certain protein substances (in weight per cent) : 



Of the oxydiamino-acids found on the hydrolysis of proteins we will 

 mention the following: 



Oxydiaminosebacic acid, (?)C 10 H 20 N 2 8 , has been isolated by WOHLGEMUTH 

 from a nucleoprotein of the liver. The free acid was obtained as small white 

 plates. It is soluble with difficulty in hot water, insoluble in cold water and 

 in alcohol. It was optically inactive in hydrochloric acid. The beautifully 

 crystalline phenylcyanate compound had a melting-point of 206. 



Dioxydiaminosuberic acid, C 8 H lr ,N 2 O 6 , has been obtained by SKRAUP 9 on the 

 hydrolysis of casein with hydrochloric acid. The copper salt crystallizes in 



1 Hedin, Zeitschr. f. physiol. chem., 21. 



2 Kossel and Kutscher, ibid., 31; Winterstein, ibid., 45; Kossel and Patten, 1. c. 



3 Kossel and Kutscher, Zeitschr. f. physiol. Chem., 31. 



4 Hart, ibid., 33. 



5 Schulze and Winterstein, ibid., 33; see also Kossel, Ber. d. d. chem. Gesellsch., 

 34, 3236. 



6 Kossel and Kutscher, Zeitschr. f. physiol. Chem., 25, and Richards and Gies, 

 Amer. Journ. of Physiol., 7. 



7 Kossel and Dakin, Zeitschr. f. physiol. Chem., 40. 



8 Bcr. d. d. chem. Gesellsch., 37, and Zeitschr. f. physiol.. chem. 44. 



9 Zeitschr. f. physiol. Chem., 42. 



