GOO 



VI. CAROTENOIDS AND RELATED COMPOUNDS 



^Pgg) 466,468 g^j.g reported to contain crocetin. Crocetin appears in the fruit 

 of the Cape jasmine or wongshi, Gardenia jasminoides (grandiflora) Lour., 

 as the glucoside crocin.''^ ^^^-^^ 



d. Related Compounds, (a) Crocin, C44H64O24. This water-soluble di- 

 gentiobiose'*^^ ester has an empirical formula of C44H64O24. Karrer and Salo- 

 mon'*®" have assigned the structure shown here to crocin. The sugar residue 



CH, 



0=c • c : c • c : c • C 



HC 



I 

 HCOH 



1 

 HCOH 



I 

 HCOH 



I 

 HC 



H H H H 

 C c: C- C 



CH, 



I H H 



C- C: C' 



OH I 

 H — C— C- 



OH OH OH I I 

 ■C— C— C— C— — CH2 



CH3 



I 



C • C = 



I 







I 



HC 



I 

 HCOH 



I 

 HCOH 



I 

 HCOH 



I 

 HC 



HaC-O- 



H H H H H 



I OH OH OH I 



-c— c— c— c— c- 



H H H H H 



OH 

 I 

 -C— H 



Crocin 



is very easily split from crocin by boiling with alkali, and crocetin can be 

 quantitatively separated. If the saponification is carried out in methyl 

 alcohol solution, an exchange esterification occurs as soon as the sugar is 

 split off, and monomethylcrocetin, as well as dimethylcrocetin, are pro- 

 duced. It was formerly believed that crocin and the two esters of crocetin 

 were all present as such in the saffron pigment; Karrer and Helfenstein^*^ 

 proved that the latter esters were synthetic products. 



(3) Azafrin 



Azafrin is a third member of the simpler carotenoid derivatives. It is a 

 monocarboxylic acid containing the |S-ionone ring and 27 carbons. 

 Maisch^^^ first obtained the pigment from the roots of the azafran or aza- 

 franillo (Escobedia scahrifolia) and gave it the name "escobedin." The 

 compound was further investigated by Liebermann,*'^^ who succeeded in 

 crystallizing it. He gave it the name azafrin. In collaboration with 

 Schiller *''' and with Miihle,^^* Liebermann did considerable work in helping 



«8 A. G. Perkin, J. Chem. Soc, 101, 1538-1543 (1912). 



«9T. Munesada, J. Pharm. Soc. Japan, No. 486, 666-671 (1922); Chem. Absl., 17 

 883-884 (1923). 



«0F. Rochleder and L. Mayer, /. prakt. Chem. [1], 72, 394 (1857); 74, 1 (1858) 

 Cited by P. Karrer and E. Jucker, Carotinoide, Birkhauser, Basle, 1948, p. 280. 



*" Maisch, cited by Dragendorf, Heilpflanzen, p. 608 (1885), and by P. Karrer and 

 E. Jucker, loc. cit., p. 291. 



"2 C. Liebermann, Ber., U, 850-851 (1911). 



«3 C. Liebermann and W. Schiller, Ber., 46, 1973-1986 (1913). 



«" C. Liebermann and G. Muhle, Ber., 48, 1653-1660 (1915). 



