5i8 PRACTICAL ORGANIC AND BIO-CHEMISTRY 

 CH H H 



HOCH 3 CH 2 



H00005: 



CH 2 -CH 2 COOII 



Hsematoporphyrin, 



In the formation of haematoporphyrin from haemin a rearrangement of the 

 bonds of the two central carbon atoms occurs and also another rearrangement 

 of the groups so that haemin probably contains a pair of condensed pyrrole 

 nuclei : 



CH 3 -C 



CH. 



A very similar formula has been put forward by H. Fischer : 

 CH=CH| |CH 3 CH 3 | |CII-CH a 



HOOC-CHgCH 



CH 2 -CH 2 -COOH 



Haemin, 



The bile pigments are closely related to haemin ; bilirubin or haemoitidin 

 is found in old blood clots ; it gives the same oxidation products and reduc- 

 tion products as haemin. H. Fischer has proposed for bilirubin the formula : 



CH 3 



Bilirubin. 



CH 2 .CH 2 .COOn 



