CAROTENOLS AND OXYCAROTENOLS OF THE C40 SERIES 559 



tunicate {Botryllus schlosseri) ^^° The carotenol has been reported in 

 several bacteria, including Mijcohacterium phlei (timothy bacillus), ^^^ in the 

 fresh-water alga {Haematococcus pluvialis) ,^" and in the olive-green, 

 branched fresh-water alga {Cladophora sauteri)}^ 



Lutein does not occur only in the free and the ester form; it has recently 

 been demonstrated by Karrer and his collaborators^"^ that it may likewise 

 be present as the epoxide. Moreover, certain well-known carotenoids such 

 as flavoxanthin have recently been proved to be closely related to the 

 lutein epoxides and to differ only in having a furnanoid structure. 



c. Related Compounds, (a) Helenien, C72H116O4. Kuhn and Winter- 

 stein""* proved this to be the dipalmitic acid ester of lutein, which may be 

 written as Ci6H3iCO-OC4oH540-OCCi5H3i. On saponification, helenien 

 yields two molecules of palmitic acid and one of lutein. It is optically 

 active. Helenien occurs with another isomer, physalien, in the following 

 flowers"^: Arnica montana (mountain arnica), Cheiranthus senoneri 

 (Greek wallflower), Doronicum pardalianches (goldbunch leopard bane), 

 Helenmm autumnale (sneeze weed), H. nudiflorwn var. grandicephalum 

 striatum (large-flowered purple-head sneezeweed), Heliopsis scabra major 

 (giant rough heliopsis), H. scabra zinniaeflora (double rough heliopsis), 

 Narcissus pseudonarcissus (common daffodil), Silphium perfoliatum (Indian 

 cup, rosinweed), Tagetes aurea (golden marigold), T. patula (French 

 marigold), T. nana Ehrenkreuz (dwarf marigold), and Tropaeolum majus 

 (climbing nasturtium). 



Karrer and Ishikawa'^^ have synthesized helenien, as well as a series of the 

 diesters of the lower fatty acids. The synthesis is readily accomplished by 

 mixing the free lutein in pyridine with the appropriate acid anhydride or 

 acid chloride. The esters are only slightly soluble in alcohol, but they dis- 

 solve readily in petroleum ether and in benzene. The following diesters of 

 lutein have been prepared and characterized^*: lutein diacetate, C44H60O4 

 (m.p., 170°C.); dipropionate, C46H64O4 (yellow-red crystals melting at 

 138°C.); dibutyrate, C48H68O4 (red platelets melting at 156°C.); di-n- 

 valerate, C50H72O4 (red-yellow platelets melting at 128°C.); di-n-caproate, 

 C\2H7604 (yellow-red platelets melting at 117°C.); diheptylate, C54H80O4 

 (yellow-red platelets melting at 111°C.); dicaprylate, C66H84O4 (yellow-red 

 platelets melting at 108°C.) ; and dipalmitate, C72HU6O4 (red needles melt- 

 ing at 92°C.). 



(b) Lutein Epoxide, C40H56O;}. Karrer and Jucker^^^ have found that 

 lutein is included among the carotenoids which may exist as epoxides. It 

 may be obtained sj^nthetically bj'" oxidation of lutein diacetate with 

 monoperphthalic acid. 



3" J. Tiacher, Z. physiol. Chem., 250, 147-154 (1937). 



"« P. Karrer and S. Ishikawa, Helv. Chim. Ada, 13, 709-713, 1099-1102 (1930). 



3's P. Karror and E. Juckor, Helv. Chim. y\da, 28, 300-315 (1945). 



