Spirazines 



15 



Anhydrides : 



Leucine anhydride 

 CH3 

 \ 



CO— NH 



CH— CH2— CH 

 CH3 NH— CO 



CH, 



/ 



CH— CH2— CH 



\ 



CH3 



Because of their frequent occurrence in living 

 tissues the formulas of creatine, uric acid, plant 

 and animal nucleic acid, and lecithin should ac- 

 company the above list: 



Creatine 



CO— OH 



/ 



H— CH 



\ 



N C==:NH 



/ I 



CH3 NH, 



Uric acid 



Plant nucleic acid 





NH 



OC 



\ 

 \ 



-CO 



Phosphoric 

 I acid 

 \ /4 



Animal nucleic acid 



(Phosphoric 

 acid 

 /4 



d-Ribose 



Desoxy- 

 Ribose 



C— NH 



^CO 



NH— C— NH 



Guanine 

 Adenine 

 Cytosine 

 Uracyl 



Guanine 

 Adenine 

 Cytosine 

 Thymine 



