Shortl) after this experience had been gained, ii 

 became valuable for understanding the ch 



i,i. ( . ill .1 nru substance extracted from .1 natural 

 organ. This substance was named lecithin l>\ in 

 discoverer, Nicolas rheodore Goble) n (1811 1876), 

 because 1"- obtained it from egg \olk (in Greek, 

 likidos). He used ethei and alcohol foi this extrac- 

 tion. Had he used water and nniici.il acid instead, 

 he would 1 k >t have found lecithin, but onl) its com- 

 ponents. As Goble) and, slighti) later, Oscat 

 Liebrei< h I 18 19 1908), subjei ted le< ithin to treatment 

 with boiling water and acid, the) separated it into 

 three parts, t me of them was the glycerophosphoi ic 

 acid of lVlnu/c, the second was the well-known steari< 

 .11 id ol Chevreul, but the thud was somewhat mwei i- 

 ous. This third substance was the same as one pre- 

 viously noticed when nerves had been subjei ted to an 

 extraction by boiling water ami acid and, therefor . 

 called nerve-substance or neurine. Adolf Friedrich 

 Strecker (1822 1871) established the identity of this 

 neurine with a product he had extracted from bile 

 and which went under the name of choline. Adolphe 

 Wuit/ 1 I .",17 1884) succeeded in synthesizing this 

 substance from ethylene oxide. CH 2 .O.CHj and tri- 

 methylamine XlCH^. 28 Thus, all three paits were 

 identified, and Strecker put them together to con- 

 struct a chemical formula for lecithin, glycerophos- 

 phoric acid combined with a fatt) acid and with 

 choline (a h\ di ate of neurine). 



loll I 

 Y'iCH.i, Choline 

 C2H4O 



TO 



C8H33O2I HO 



CeHaiOij CsHsOj 



Fatty acids Glycerophosphate 



Lecithin 

 according to Strecker 



This formula was not quite correct. Richard 

 Willstatter showed that an internal neutralization 

 takes place between the amino group and the free 



acidic residue. This is expiessed in his lecithin 

 formula of I'M;:. 



" X. I. Gobley, Comptts-rcndus .... Paris (184 i . vol. .'1. 



p. 71!'.. 



-\V Wurtz, Comptts-rendtu ... Pari '■'>. p. 



772. 



CH •() II 



1 

 ( ll.-OH, 



o-cHeCii. 

 / \ 



( ||,o— 1> = N(CH 3 ).i 



Lecithin (1918) 



When the aim was tO distill e|n i ient.il \ phosphorus 



out ol .hi organii material, 11 did not matter whether 

 this was fresh or puti it led. For obtaining lecith 

 ol yolk and similar materials, it was essential to 



use it in fresh condition. < )therwise, enzymes would 



have decomposed it. Through mine recent work. 



lour enzymes have been separated, which act spec ifi- 

 i.ilK in decomposing lecithin. Enzyme A removes 



(Hie fatt) .11 id and leaves a complex residue, called 



lysolecithin, intact. Enzyme B attacks this residue 

 and splits dll the remaining fatt) acid group from it, 

 enzyme ( '■ liberates only the choline from lecithin, and 

 enzyme 1> opens lecithin at the ester bond between 

 glycerol and phosphoric acid. This is shown in the 

 following diagram. 



ENZYMA 1 H Sim i i i ixi, i if LeCII iuxs 



].\/\ \n Si lis 1 1; \ 11 



I'ki i|)i lis 



Several lain acids can he present in lecithin from 

 various sources: palmiti< and oleic acid, besides the 

 stearic acid which at first had been thought the onl) 



one involved. In another group of extracts from 



brain or nerve tissue, amino-ethanol I FN ( II. < I F< Ml 



is found instead of the choline of lecithin. The 

 variations include the alcohol, to which the fatt) 



acids ->iu\ ( holine phosphate are attached. For exam- 

 ple, glycerol can he replaced by the so-called 

 sugar, inositol, which has six hydroxy! groups in its 

 hexagon-shaped molecule ( t H,i< 'H) f ,. 



Ill, generall) similar behavior of these phosphate- 

 and fat-containing substances was emphasized l>\ 



l' \i'i r in: iiisic >ry c 11 I'm isi'hori's 



191 



