TETRAPYRROLES 



43 



TABLE 3 

 Chlorophyll derivatives accumulated by photosynthetic microorganisms 



Compound 



Accumulated by 



Reference 



Mg-protoporphyrin 



Mg-protoporphyrin 

 monomethyl ester 



Mg-vinylpheoporphyrin 

 a 5 (protochlorophyll- 

 ide a) 



Protochlorophyll-type 

 pigments 



Pheophorbide a 



Chlorella mutant 



Chlorella mutant 

 Rps. capsulata 

 Rps. spheroides 

 Chlorella mutant 



Rps. spheroides chlorophyll- 

 less mutants 



Rps. spheroides carotenoid- 

 less mutants* 



(34) 



(34) 

 (17) 

 (18) 



(35) 



(36) 

 (37) 



(38) 



* This mutant excretes a variety of chlorophyll derivatives of which pheo- 

 phorbide a and a closely related compound are the major components; a minor 

 component has the tetrahydropyrrole ring system of bacteriochlorophyll and is 

 probably bacteriopheophorbide. 



Mg Me 



Protoporphyrin »- Mg-protoporphyrin ^Mg-protoporphyrin monomethyl ester 



donor 



4-5 steps 



holochrome complex 



Light 



Chlorophyll a t Chlorophyllide o Mg-vinvlpheoporphyrin a 5 



I I t D..-^ r - 



bacteriochlorophyll pheophorbide a 



Scheme 2. Possible pathways from protoporphyrin to chlorophylls. 



