LUTEIN. 631 



phosphatide, soluble with difficulty in ether, but obtained in crystalline 

 needles from hot alcohol, and contained 2.77 per cent N and 3.22 per cent 

 P, and had a melting-point of 160-170 C. FRANKEL and BOLAFFIO l 

 also found a substance crystallizing from hot alcohol and insoluble in 

 ether with 2.78 per cent N and 2.18 per cent P. They call this body 

 neottin and claim that it is a triamino-monophosphatide having the formula 

 Cs4Hi72N3POi5. BARBIERI has obtained a sulphurized phosphatide 

 called ovin, containing 1.35 per cent P, 3.66 per cent N and 0.4 per cent S. 

 The relation of all these bodies to each other must be further studied. 



Lutein. With the name lutein we in the past have included several 

 yellow or orange-red amorphous coloring-matters which occur in the 

 yellow of the egg, and in several other places in the animal organism; 

 for instance, in the blood-serum and serous fluids, fatty tissues, milk- 

 fat, corpora lutea, and in the fat-globules of the retina as well as in dif- 

 ferent plants (THUDICHUM). Among these bodies belong the crys- 

 talline substance obtained by ESCHER from the corpora lutea (page 623). 

 It was difficultly soluble in alcohol but readily soluble in petroleum ether 

 and showed itself isomeric or perhaps identical with the plant pigment 

 carotin (C^Hse) analyzed by WILLSTATTER and MIEG. The lutein of 

 the egg yolk, which is more readily soluble in alcohol and less soluble in 

 petroleum ether than carotin has also been obtained by WILLSTATTER and 

 ESCHER in a pure, crystalline form. On analysis it gave the formula 

 C4oH5e02. As shown by C. A. SCHUNCK the yolk lutein stands in 

 close relation to the yellow plant pigment, xanthophyll. The formula 

 given by WILLSTATTER and ESCHER for lutein was in fact the same as 

 for the xanthophyll, as previously found by WILLSTATTER and MIEG. 

 These two substances are also similar in other respects; still the melting- 

 points of the two are different. The carotin and the yolk lutein differ 

 also by the absorption spectra, which is different in different solvents 

 as well as by their formulae and different solubilities. 2 



The relation of the other substances called luteins to each other and 

 to the yolk lutein is unknown. All are soluble in alcohol, ether, and chloro- 

 form. They differ from the bile-pigment, bilirubin, in that they are not 

 separated from their solution in chloroform by water containing alkali, 

 and also in that they do not give the characteristic play of colors with 

 nitric acid containing a little nitrous acid, but give a transient blue color. 

 The luteins withstand the action of alkalies so that they are not changed 

 when we remove the fats present by means of saponification. 



1 Thierfelder and Stern, Zeitschr. f. physiol. Chem., 53; Frankel and Bolaffio, 

 Bioch. Zeitschr., 9; Barbieri, Compt. Rend., 145. 



2 Thudichum, Centralbl. f. d. med. Wiss. 1869; Willstatter and Mieg. Ann. d. 

 Chem., 355 (1907); Willstatter and Escher, Zeitschr. f. physiol. Chem., 64 (1909); 

 76 (1911); Schunck, see Chem. Centralbl., 1903. 



