KEPHALIN 55 



Treat the solution with a stream of carbon dioxide until no 

 more barium carbonate comes down. Filter and evaporate 

 the filtrate to dryness. Treat the residue with absolute alcohol, 

 which will dissolve the choline but not the barium glycero- 

 phosphate. The alcoholic solution, if treated with an alcoholic 

 solution of platinic chloride, gives a precipitate of the double 

 platinichloride of choline. 



Green and Jackson * give the following method : Allow the 

 finely-divided material to stand for some days under absolute 

 alcohol. Pour off the extract, and evaporate to dryness ; the 

 residue is again extracted with absolute alcohol, and finally 

 with a mixture of alcohol and ether. These extracts are 

 mixed, and the solvents evaporated off. The choline is con- 

 tained in the residue. 



In addition to the above products of the hydrolysis of 

 lecithin of animal origin, a number of phospholipins isolated 

 from the seeds of Avena saliva, Lupinus spp, Pinus cemhra as 

 well as from pollen and potato tubers yield glucose, galactose, 

 and pentoses. t 



KEPHALIN. 



This is the name given to a phospholipin whose nitrogen 

 base is aminoethyl alcohol, NHgCH^CHaOH, in place of 

 choline ; its chemical constitution is closely allied to that 

 of lecithin but it differs from this substance probably in the 

 nature of the acid radicles it contains. It occurs together 

 with lecithin in most animal and vegetable tissues ; as ex- 

 amples of the latter may be mentioned the soya bean % and 

 yeast. § 



Kephalin, unlike lecithin, is practically insoluble in alcohol, 

 and the two substances may be separated by making use of 

 this fact. 



Betaine has likewise been described as replacing choline 

 as the nitrogen base of a phospholipin, by Zlataroff.jl 



* Green and Jackson : " Proc. Roy. Soc," B., 1906, 77, 69. 

 t Winterstein and Hiestand : " Zeit. physiol. Chem.," 1906, 47, 496 ; 

 1908, 54, 283 ; Zlatarov : " Biochem. Zeit.," 1925. 161, 399- 

 X Levene and Rolf : " J. Biol. Chem.," 1925, 62, 759. 

 § Daubney and Smedley-Maclean : " Biochem. Journ.," 1927, 31, 373. 

 11 Zlataroft : " Biochem. Zeit.." 1925. i6l, 379- 



