122 ESSENTIALS OF CHEMICAL PHYSIOLOGY 



Hypoxanthine or Sarcine is found in the body tissues and fluids, 

 and in the urine. It is derived from some nucleins, especially those 

 from fishes' spermatozoa. It may be termed 6-oxypurine, as the 

 oxygen is attached to the atom numbered 6 in the purine nucleus. 



Xanthine is found with hypoxanthine in the body, and has been 

 obtained from a number of nucleins (from spermatozoa, thymus, 

 pancreas, &c.). It is 2, 6-dioxypurine, its oxygen atoms being 

 attached to the atoms numbered 2 and 6 in the purine nucleus. 



NH-C = NH-C=0 



II II 



H - C G - NH. 0=0 C -NH. 



II II >C-H I II >C-H 



N- 0- N^ NH-C- N^ 



[hypoxanthine] [xanthine] 



Adenine is found in the tissues, blood, and urine. It is obtained 

 from several nucleins, but especially from the nuclein derived from 

 the thymus. It is 6-amino-purine. 



Guanine is also a decomposition product of nucleins, especially 

 of that obtained from the pancreas. Combined with calcium it 

 gives the brilliancy to the scales of fishes, and is also found in the 

 bright tapetum of the eyes in these animals. It is a constituent of 

 guano, and here is probably derived from the fish eaten by marine 

 birds. It is 2-amino-6-oxypurine. 



N=0-NH2 NH-C = 



I I I I 



H - - NH. H2N — - NH. 



II II >C-H II II >C-H 



[adenine] [guanine] 



Uric Acid is 2, 6, 8-trioxypurine. 



NH - = O 



0=0 - NH 



I II ^CO 



NH-O-NH/ 



[uric acid] 



We thus see the close relationship between uric acid and the 

 nuclein bases. Leaving aside other possible ways in which uric 

 acid is undoubtedly formed in the organism, we have here a way in 

 which uric acid may arise by oxidation from the nuclein bases and 

 thus ultimately from the nuclei of cells. Certain forms of diet 

 increase uric acid formation by leading to an increase of leucocytes 



