200 BACTERIOLOGICAL AND ENZYME CHEMISTRY 



Purin Bases 



These important substances are obtained as decomposition 

 products of nucleic acid, produced in its turn from so-called 

 nucleo albumins. They are derived from a parent substance, 

 prepared by Bmil Fischer, which he termed purin. The 

 relation of the purin bases to purin is shown by the following 

 formulse : — 



Purin 



Guanin 



Xanthin 



Adenin 



