CAROTENOIDS OF THE C40 SERIES 587 



4. Structure and Occurrenci' of Carotenoids of the C40 Series 

 Primarily of Animal Origin 



(/) Astacene 



The coloring matter of Crustacea is of considerable interest to the chemist 

 and I lie zoologist. One important pigment of this type was first isolated by 

 Kuhn and Ledcrer in 1933^"" in the shell, hypodermis, and eggs of the Nor- 

 wegian lobster {Astacus gammarus, also known as Homarus vulgaris). It 

 was called astacene. It was partly bound with protein and, in part, com- 

 bined as a dipalmitate ester. The stmcture of astacene was largely clari- 

 fied through the investigations of Karrer and his collaborators. ^"^"^"^ 

 Astacene was found to be a tetraketone with the composition C40H48O4. It 

 was showTi to be 3,4,3',4'-tetraketo-j8,/3'-carotene. 



Astacene (enol form) 



Astacene has been demonstrated chiefly in the Crustacea. Karrer et al.^^ 

 found it in the esterified form (astacein) in the shells of lobsters and crabs. 

 However, it has also been reported in the eggs of the spider crab {Maia 

 squinado)^'^'' and in the dark red brittle sea star (Ophidiaster ophidianus) .'^'^^ 

 Other Crustacea in which astacene has been noted include some lobsters, ^''^ 

 such as Palinurus vulgaris (European rock lobster, or langouste), a Euro- 

 pean river crayfish (Potamohius astacus or Astacus fluviatilis) , the small 

 Norway lobster (Nephrops norvegicus) ,'^'^^ the red pra^vn {Leander serratus), 



^"2 R. Kuhn and E. Lederer, Ber., 66, 488-495 (1933). 

 ^«3 P. Karrer and F. Bcnz, Helv. Chim. Acta, 17, 412-416 (1934). 

 «4 P. Karrer and L. Loewe, Helv. Chim. Acta, 17, 745-747 (1934). 

 ^«5 p. Karrer, L. Loewe, and H. Hubner, Helv. Chim. Acta, 18, 96-100 (1935). 

 «« P. Karrer and H. Hul)ner, Helv. Chim. Acta, 19, 479-480 (1936). 

 «^ R. Kuhn, E. Lederer, and A. Deutsch, Z. physiol. Chem., 220, 229-235 (1933). 

 *<» G. N. Burkhardt, L M. Heilbron, H. Jackson, E. G. Parry, and J. .\. Lovern, 

 Biochem. J., 28, 1698-1701^(1934). 



