SYNTHESIS OF THE PORPHYRIN NUCLEUS 



633 



the mother substance, since by spHtting of the benzene nucleus and 

 removal of the amino group one can, on paper, arrive at a pyrrole 

 substituted with the right kind of side chains: ,, 



^ 



,CHtCHC02H 



I 

 NH, 



H 



We have seen above (Section 3.2.3.) that there is no evidence that 

 tryptophane is needed for the synthesis of porphyrin. Other theories 

 leave the side chains out of account. Abderhalden suggested ring 



Hemoglobin 



A 



Fig. 1. Porphyrins occurring in the animal body: broken lines, small amount of 

 formation normally; dotted lines, mainly pathological. 



