522 PRACTICAL ORGANIC AND BIO-CHEMISTRY 



The Action of Acids. Removal of the Magnesium. 



The action of very dilute acid, oxalic acid or even hydrochloric acid, upon 

 chlorophyll d and chlorophyll b is to remove the magnesium without changing 

 the molecule, except that hydrogen takes the place of the magnesium. Dilute 

 acid also removes the magnesium from the products formed by the action of 

 alkali. A series of compounds is thus obtained : 



COOH 



NlT 



CO 



Chlorophyllin a. 



COOCH 3 

 Chlorophyll b. 



COOH 



co 



NH 



Isochlorophyllin a. 



COOH 



COOCH, 



Phaeophytin a. 



COOC 20 H 39 



COOCH S 

 Phaeophytin b. 



COOH 



COOH 



Phytochlorin e. 



COOH 



COOH 

 Isochlorophyllin b. 



., 



COOH 



Phytorhodin g. 



C 3 ,H 32 ON 4 



COOH 



COOH 



NH 



Chlorophyll a. 



.COOH 

 '\COOH 



Phytochlorin/ and g. 

 Phytorhodin i and k ( 



.COOH 

 / 

 \COOH 



CsiH^N.Mg 



Chlorophyllin b 



Cyanophyllin 



Erythrophyllin 



Rubiphyllin 



Glaucophyllin 



Rhodophyllin 



Phyllophyllin 



Aetiophyllin CjjH^N^g -> Aetioporphyrin C 31 H 86 N 4 



Phaeophytin a and phaeophytin b have the same composition as chloro- 

 phyll a and chlorophyll b, except for the presence of magnesium. They are 



COOH Cyanoporphyrin ^ 

 / ^ > Erythroporphyrin I ^ 



\ Rubiporphyrin V C 31 H 34 N 4 \ 



\COOH Glaucoporphyrin \COOH 



Rhodoporphyrin } 



