HEXON BASES. 423 



been designated by Kossel as the hexon bases inasmuch as they con- 

 tain six carbon atoms. 



Arginin the first known, and perhaps the most important member 

 of this group, was discovered by Schulze and Steiger* in 1886 in 

 lupine sprouts wherein it is formed as a result of the energetic pro- 

 teid disintegration which takes place in the developing plant. The 

 base exists preformed in the cotyledons inasmuch as it can be ex- 

 tracted from these by water alone without the aid of hydrolytic 

 agents. In this way the dry sprouts yielded as much as 3.5 per 

 cent, of arginin. Nine years later Hedin^ demonstrated that 

 arginin could be obtained by the hydrolytic cleavage of a number 

 of proteid substances. On decomposing these by boiling with hy- 

 drochloric acid and tin, he obtained variable amounts of the base as 

 shown below and at no time was the quantity as large as that ob- 

 tained by Schulze from sprouts. 



The yield was as follows : 



Conglutin, 2.75 per cent. Egg albumin, 0.8 per cent. 



Gelatin, 2.6 " " Blood serum, dried, 0.7 " " 



Horn, 2.5 " " Casein, 0.25" " 



Yolk albumin, 2.3 " " 



As yet no proteid is known which does not yield arginin on 

 hydrolysis. Elastin which was studied by Berg and by Hedin was 

 supposed to be free from arginin but Kossel and Kutscher ' showed 

 by means of improved methods, that it did contain about 0.3 per 

 cent, of the base. Subsequently lysin was also shown to be present. 

 Of the total nitrogen contained in the young spfouts of pine and fir 

 21 to 29 per cent., according to Schulze,* is represented by arginin 

 while the proteid from the seeds of the same plants on cleavage with 

 hydrochloric acid and tin yield as much as 10 per cent, of the base. 

 On a subsequent occasion a yield of only 6 per cent, was obtained 

 from fir seeds. The proteids contained in the seeds of plants are 

 apparently extremely rich in arginin which is set free during the 

 active proteid destruction which ensues during germination. This 

 becomes readily comprehensible when it is remembered that tryptic 

 ferments are brought into being in the process of germination 

 (Butkewitch) and that the hydrolytic cleavage which these ferments 

 induce is analogous to that produced by acids, and corresponds to 

 the pancreatic digestion of proteids. This fact will be rendered the 

 more apparent on comparison of the digestion products formed by 

 trypsin and the following bodies which Schulze ° has isolated and 



^Zeits. phygiol. Ghem., 11, 44 (1886). 



sZeite. phygiol. Ghem., 21, 155 (1895); 20, 186 (1894). 



^Zeits. physiol. Ghem., 25, 551 (1898) ; 31, 205. 



'Zeits. physiol. Ghem., 22, 435 ; 25, 360. 



5 Zeits. phygiol. Ghem., 28, 470. 



