CAROTENOIDS IN PLANTS 



The apo-carotenes were first produced by Karrer and his school' ^ 

 by controlled oxidation of naturally-occurring carotenoids and 

 this is the first time that they have been reported to occur naturally. 



It is important, therefore, that C. infundibiliformis should be re- 

 investigated in the light of present knowledge, because Willstaedt's 

 pigment may turn out to be either an epoxide or a pigment similar to 

 neurosporene. 



When the general properties of Willstaedt's pigment are considered 

 in the light of present knowledge, it appears much more likely to be 

 neurosporene than p-apo-8'-carotenal. 



Recently Haxo ^ ®^ has examined the related species C. cinnabarinus . 

 Of the complex mixture of pigments obtained only two were identified 

 with known carotenoids, viz., p-carotene and phytofiuene. Two (III 

 and VI) of the remainder were obtained chromatographically pure but 

 not crystallized ; they were adsorbed just above lycopene and p- 

 carotene respectively. A third was obtained crystalline and found to 

 be a new xanthophyll ; it was named canthaxanthin {see Table 6). 



SCHIZOMYCETES 



Of the two families of anascoporogenous yeasts the Rhodotorulaceae 

 contain carotenoids and the Torulopsidaceae do not. '^ Zopf^^ was 

 the first to notice carotenoids in the red yeasts and in 1916 Chapman ' *■ 

 noted that the absorption spectrum of the carotenoid extracted from 

 red yeast was different from that of carotene. The more recent inves- 

 tigations of Lederer ^'^^^^ on three strains of Rhodotorula rubra have 

 to a considerable extent elucidated the carotenoid composition of this 

 yeast. Each strain contained the same 4 pigments : 



(1) an acidic pigment (XX^ax. 583, 545, 500 m.]x. in CSg), 



(2) p-carotene, 



(3) torulene, 



(4) an unstable carotene which could not be examined in detail. 



Me 



Me Me Me Me' 



>OMe 



Torulene 



Lederer considers torulene to be 3 : S'-dimethoxy-y-carotene but he 

 emphasizes that this is by no means proved. It is inactive as a vitamin 

 A precursor. ' •» * ' 



105 



