320 CAROTENOIDS OF UNCERTAIN STRUCTURE XIV 



evidently not the hypophasic pigment of Chargaff, since the latter exhibits 

 absorption maxima at longer wavelengths. 



Very recently the pigments of Sarcina lutea have been reinvestigated by 

 YosHiHARU Takeda and Tatuo Ohta^^ who described the isolation of a new 

 carotenoid which they termed sarcinaxanthin. From 385 g of dried bacteria, 

 3.4 mg of sarcinaxanthin were obtained. The pigment crystalhsed from a 

 mixture of benzene and petrol in tufted red spheroids, m.p. 149-150° (Kofler- 

 HiLBCK micro-melting point apparatus). On partition between petroleum 

 ether and methanol, sarcinaxanthin behaves like a phytoxanthin containing 

 one hydTOxyl group. It is fairly strongly adsorbed on alumina fiom petrol 

 solution and can only be eluted with difficulty by means of petrol containing 

 some ethanol. 



Solvent Absorption maxima 



Carbon disulphide 499 466.5 436 m/< 



Chloroform 480 451 423 m/< 



Petrol 469 440 (415) m// 



Benzene 481 451 424 m/z 



Ethanol 469.5 441 (415) m/x 



It appears that sarcinaxanthin may be identical with the hypophasic 

 carotenoid reported — though not isolated — by Chargaff^^- ^*. 



15. TARAXANTHIN C4oH5g04 



History and Occurrence 



During an investigation of the carotenoids from the blossoms Taraxacum 

 officinale (dandelion), Kuhn and Lederer" discovered a new pigment which 

 they termed taraxanthin. Later studies by Karrer and Rutschmann^s showed 

 that the occurrence of taraxanthin evidently depends on geographical and 

 chmatic factors since the material investigated by the last-named authors did 

 not contain the pigment. 



Numerous references to the occurrence of taraxanthin are given in the 

 Hterature, but the pigment never occurs in large concentrations and its 

 isolation is relatively tedious. 



References p. 241-343. 



