434 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



adenin, hypoxanthin is formed as a by-product, provided the arnino- 

 group is replaced primarily. 



HN CO 



HN CO 



I I 

 NH 2 C C NH 



>CH 



N C N 



Guanin. 



OC C NH 

 HN C N 



Xanthin. 



H 



N=C.NH 8 



I I 

 HC C NH 



N C N 



Adenin. 



CH 



The following table shows the effects of enzyme - action and 

 of hydrolysis by means of boiling acids on the nucleo - proteids 

 of the thymus, the suprarenal, and the spleen, according to Walter 

 Jones : 



These results might be explained by assuming that the enzymes anc 

 the mineral acids attack the nucleic acids at different points, am 

 thereby give rise to different products ; but Walter Jones is of tb 

 opinion that the enzymes act in exactly the same way as do boilin| 

 mineral acids, and that, in addition, they have the power of removin/ 

 amino-groups, and of oxidising and of splitting up C0 2 . " It i 

 interesting that these three effects are produced by the ordinar; 

 putrefactive bacteria, as in the formation of paroxyphenyl-propioni 

 acid, paracresol and phenol from tyrosin, and in the formation c 

 putrescin from a-S-diamino-valerianic acid." 



Jones and Partridge 1 then studied the differences between th 

 purin-derivatives formed during autodigestion and those formed b 

 hydrolysis of the corresponding nucleo-proteids by means of boilin 

 mineral acids. They found the pancreas to contain an enzym 

 capable of converting guanin into xanthine, and they called tb 



W. Jones and C. L. Partridge, Zeit. /. 



Chem. 42. 343 (1904). 





