HYDROCARBON CAROTENOIDS OF THE C40 SERIES 527 



HjC CHj HjC CHj 



Q CHj CH; CH; CHj C 



/\ hhIhhhIhhhhIhhhIhh /\ 

 HzC c-c:C'C:C'C:C'C:C'C:c-C:C'C:c-C:C-c:c-c CH2 



I l> 0(1 1 



HjC C C CH2 



\ / \ / \ / 



C CHj H3C C 



H2 H2 



/3-Caroteue di-epoxidc 



Karrer et a7.^^^ report that epoxides are naturally present in plant but 

 not in animal tissues. It is suggested that they may be changed to the 

 furanoid structure in the plant. The epoxides possess considerable l^iologi- 

 cal activity and, in fact, they are to some extent convertible to carotenes in 

 the test tube when treated with hydrochloric acid. Maximum vitamin A 

 activity was produced by daily doses of 10 y of jS-carotene epoxide and 17 7 

 of /3-carotene di-epoxide. ^"^ 



(rf) Luteochrome, C40H55O2. When /3-carotene is oxidized with perphthal- 

 ic acid, luteochrome originates in addition to /3-carotene mono-epoxide 

 and j8-carotene di-epoxide. It crj^stallizes in thin yellow-orange platelets 

 from a benzene-methanol mixture. It melts at 176°C. When it is treated 

 with concentrated aqueous hydrochloric acid, its behavior is similar to 

 that of /3-carotene di-epoxide and aurochrome. When it is partitioned be- 

 tween methanol and petroleum ether, most of it goes into the upper layer. 



H3C CH3 

 \ / 



HjC CH3 A 



\ / H / \ 



Q CHj CHj CHj HjC C=^C CHs 



/xhhIhhhIhhhhIhhhII | | 



HzC c^ C : C • C; C • C: C • C: C • C: C' C: C • C: C • C: C • CH C^ /CH2 



I i> V/V 



HzC C HjC Hj 



\ / \ 



C CH; 



Hz 



Luteochrome 



The j3-carotene epoxides and the furanoid derivatives may be separated 

 from each other by chromatographic analysis, using a column of calcium 

 oxide, and petroleum ether as the solvent. These oxides have the same 

 qualitative and quantitative solubility properties as does /3-carotene. 

 They dissolve well in carbon disulfide, chlorofonn, benzene, and ether, 

 somewhat less readily in petroleum ether and with difficulty in methanol 

 and ethanol. 



(e) Oxy-^-carotene, C40H58O2. This compound is closely related to /3- 

 carotene oxide, except that hydroxyl groujis have been inti'oduced at posi- 

 tions 5 and G. These take the place of the single oxygen in tlie bridge 

 structure between these carbons. Oxy-/3-carotene originates through the 

 oxidation of /3-carotene with aqueous 0.1 .Y chromic acid. It crystallizes 



