200 BACTERIOLOGICAL AND 



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 Emil Fischer, which he termed purin. The 

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

 formulae : 



Purin 



Guanin 



= HC C-NH 



N-C-N 



X 



CH 



C 5 H 5 ON 5 



HN-CO 



! I 



NH 2 C C-NH 



Xanthin .. C 5 H,0 2 N 4 = 



Hypoxanthin C 5 H 4 ON 4 = 





HN-CO 



I I 

 OC C-NH 



\ 



CH 



HN-CO 



I I 

 HC C-NH 



\ 



CH 



N=CNH 



Adenin .. C 5 H 5 N 5 = HC C-NH 



N-C-N 



CH 



