180  Constituents  of  Taraxacum  Root.  {Am^\n^m 
lisation  from  alcohol,  it  separated  in  long,  colorless  needles,  melting 
at  221 — 2220  : 
0.1999,  when  heated  at  125  °,  lost  0.0198  H20.    H20  =  9.9. 
0.0848  3  gave  0.2625  C02  and  0.0902  H20.    C  =  84.4;  H  =  11.8. 
0.0737  3   "    0.2284  C02    "    0.0772  H20.    C  =  84.5  ;  H  =  1 1.6. 
C29H480,2^H20  requires  H20  =  9.8  per  cent. 
C29H4S0  requires  C  =  84.5  ;  H  =  11.6  per  cent. 
It  is  evident  from  these  results  that  the  above-described  compound 
possesses  the  formula  C29H480,  and,  being  a  new  alcohol,  having 
properties  similar  to  those  of  the  phytosterols,  it  is  proposed  to 
designate  it  taraxasterol,  with  reference  to  the  source  from  which 
it  has  been  obtained. 
A  determination  of  its  optical  rotatory  power  gave  the  following 
result : 
0.4343,3  made  up  to  20  c.c.  with  chloroform,  gave  aD  -f-40  11'  in  a 
2-dcm.  tube,  whence  [a]  D  +96.3  °. 
Taraxasterol  is  homologous  with  two  monohydric  alcohols  previ- 
ously isolated  in  these  laboratories  from  the  rhizome  of  Apocynum 
androscemifolium,  namely  androsterol,  C30H50O,  and  homo-andro- 
sterol,  C27H440  (Trans.,  1909,  95,  739),  and  it  gives  a  color 
reaction  similar  to  that  yielded  by  the  last-mentioned  compounds  ; 
thus,  if  a  small  amount  of  the  substance  be  dissolved  in  chloroform 
with  a  little  acetic  anhydride,  and  a  few  drops  of  concentrated 
sulphuric  acid  subsequently  added,  a  pink  color  is  produced,  which 
slowly  changes  to  a  dark  magenta  with  a  green  fluorescence,  and 
this  color  persists  for  several  hours.  The  above-mentioned 
alcohols,  together  with  a  homolo>gue  of  taraxasterol  to  be  sub- 
sequently described,  C25H40O,  constitute  four  members  of  a  group 
which  is  represented  by  the  general  formula  Cn  H£n-10O. 
Acetyltaraxasterol,  C29H47O.CO.CH3. — This  compound  (m.  p. 
251 — 2520),  the  preparation  and  characters  of  which  have  already 
been  described,  was  dried  at  1200  and  analysed: 
0.0866  gave  0.2602  C02  and  0.0854  H20.    C  —  81.9;  H  =  10.9. 
0.0824    "    0.2472  CO,    "   0.0810  H20.    C  =  81.8;  H  =  10.9. 
C31H50O2  requires  C  =  8i-9;  H=  11.0  per  cent. 
3  Dried  at  1200. 
