Lecithin. 
(Am.  Jour.  Pharm. 
\      April,  1914. 
lytic  experiments,  have  expressed  doubt  as  to  the  possibility  of  an 
ester-like  combination  between  choline  and  phosphoric  acid.  It  is 
certainly  true  that  the  natural  lecithins,  however  carefully  they  are 
purified,  always  represent  mixtures  of  various  lecithins.  The 
physical  condition  of  pure  commercial  lecithin,  which  is  waxy  and 
occasionally  somewhat  crystalline,  is  in  favour  of  this  view ;  and  it  is 
justifiable  to  assume,  according  to  the  present  position  of  research 
on  lecithin,  that  the  separate  lecithins  which  constitute  natural 
lecithin,  in  their  absolute  chemical  individuality  and  purity,  are 
crystalline  bodies. 
The  solution  of  this  problem  is,  however,  of  more  chemical  than 
physiological  or  therapeutic  interest.  As  is  evident  from  an  inves- 
tigation by  Stepp,  those  lecithins  alone  are  of  physiological  or  thera- 
peutic importance  which  are  produced  by  the  living  organism  itself 
for  its  own  use.  It  is  therefore  probably  justifiable  in  therapeutics 
to  speak  of  pure  lecithin  when  this  consists  solely  of  lecithins  with- 
out admixture  of  albumins  or  of  lecithalbumins.  My  Lecithinum*ex 
ovo  purissimum  is  a  preparation  of  this  nature. 
The  discovery  of  lecithin  is  usually  attributed  to  Gobley  (1846), 
although  long  before  him  Vauquelin  (1811)  and  Couerbe  (1834) 
found  and  described  phosphorus-containing  fats  in  the  brain,  which 
were  probably  identical  with  lecithin.  Fremy,  a  pupil  of  Couerbe, 
named  Vauquelin's  substance  "  oleo-phosphoric  acid,"  as  he  found 
its  products  of  decomposition  to  consist  of  glycerin,  phosphoric 
acid  and  oleic  acid.  In  conjunction  with  Valencienne  he  isolated  the 
same  substance  from  the  roe  of  fish.  But  Gobley  was  the  first  to 
prepare  it  from  the  yolk  of  eggs,  and  he  called  it  "  matiere  vis- 
queuse,"  and  later,  on  account  of  its  origin,  "  lecithin,"  from 
Aex-i&og  (=yolk  of  egg).4  He  was  also  the  first  to  recognise  the 
principal  component  of  lecithin  possessing  physiological  importance, 
namely  glycerophosphoric  acid,  which  is  obtained  by  the  careful 
saponification  of  lecithin;  he  thus  established  the  basis  for  the  con- 
stitution of  the  lecithin  molecule  which  is  still  fairly  generally 
accepted.  The  basic  component  of  lecithin,  choline,  was  discovered 
by  Liebreich  and  Strecker. 
Lecithin  is  therefore  regarded  as  a  glycerophosphoric  acid  in 
*  Strecker's  view  (Annalen  der  Chemie  und  Pharmazie,  1868,  Vol.  72,  p. 
77)  that  the  word  lecithin  is  derived  from  floe  (=  oil  jar)  and  should 
therefore  be  written  lecythin,  is  erroneous. 
