PIGMENTS 109 



By reduction, there have been obtained from the chlorophylls 

 and the various porphyrins, three isomeric pyrrole derivatives 

 having the following formulas, 



CHs CHs 



C2Hs C=C\ C2Hs C=C\ C2Hs C = C\ 



| ^yNH | ^>NH | ^>NH 

 CHs C := C CHs C^C CHs C^=C 



I I I 



CH 3 CH 3 H 



Phyllopyrrole Hsemopyrrole Isohaemopyrrole 



As a result of the study of these decomposition units, Will- 

 statter has suggested the following formulas for the structural 

 arrangement of aetiophyllin and aetioporphyrin, the compounds 

 which result from the removal of all of the acid groups and finally 

 of the magnesium from the chlorophylls, 



H HC=CH H HC=CH 



CH 3 -C-CX C-C CH 3-- C V i-C 



II > . NT II II ;N N^ H 



CTJ f-* f-*' / ^f ~f H t~* T-I f~* f~* ' t~* /^T.T 



2H 5 "C-C^ \ / #+ ^^ *-2**5"^"^^ IC-CU 



^cW/ \ o 7 



\ / C = C CoHc 



N, v /i * & '" " [ \ , 

 | ^N-Mg-N( I )N ., 



CH 3 -C=Cf X C =C ' CH 3 CH 3 -C=C N>C-CH 3 



CH 3 CH 3 tH 3 CH 3 



aetiophyllin aetioporphyrin 



The COOH groups which are attached to these compounds to 

 form the various phyllins and porphyrins, as well as the original 

 chlorophylls, are supposed to be attached to the C2Hs groups in 

 the above formulas, the different modifications, or compounds, 

 depending upon the position in which one or more of these attach- 

 ments are made. 



SIMILARITY OF CHLOROPHYLL AND HEMOGLOBIN 



It seems to be desirable, at this point, to call attention to the 

 remarkable similarity in the chemical composition of chlorophyll, 

 the most important pigment of plants, and haemoglobin, the all- 

 important respiration-regulating pigment in the blood of animals. 



