110  Active  Constituents  of  PodophylUn.         { "^"MaT'iSr" 
The  extractive  matters  of  officinal  podophylliii,  of  which  nothing 
special  can  be  .said,  are  all  of  a  dirty  grayish-brown  color,  and  of  the 
consistence  of  sticky,  soft  resins ;  they  are  without  action  on  tlie  ani- 
mal organism. 
Methods  of  Obtaining  the  Constituents. — Pure  podophylloquercetin 
can  be  obtained  best  from  podophyllin  prepared  specially  for  this  pur- 
pose. All  the  other  above-mentioned  bodies,  Avith  the  exception  of 
the  picropodo23hyllinic  acid,  can  be  obtained  more  conveniently  and 
purer  from  the  rhizome  than  from  commercial  podophyllin.  The 
picropodophyllinic  acid  can  only  be  obtained  from  the  podophyllo- 
toxin. 
The  podophyllotoxin  is  perfectly  adapted  for  therapeutic  uses,  being 
readily  assimilated  by  the  animal  organism,  as  proved  by  clinical  expe- 
riments made  with  it  in  Vienna,  and  also  by  the  experience  of  private 
practice.  The  crystallized  picropodophyllin  is  in  this  respect  less 
applicable  on  account  of  its  unfavorable  conditions  of  solubility. 
The  best  and  simplest  method  for  obtaining  pure  podophyllo- 
toxin for  medicinal  use  is  the  following :  Podophyllum  in  coarse 
powder  is  extracted  by  digestion  with  chloroform  for  2  days  at  ordi- 
nary temperatures  in  a  glass  vessel  or  percolator,  with  frequent  agita- 
tion. If  a  glass  vessel  is  used,  the  product  of  the  first  digestion  is 
poured  off,  a  fresh  portion  of  chloroform  added,  again  decanted,  and 
subsequently  a  third  portion  of  chloroform  added,  whereby  each 
time  an  amount  of  chloroform  equal  to  or  somewhat  more  than  that 
of  the  weight  of  the  podophyllum  should  be  employed.  If  a-perco- 
lator  is  used,  fresh  portions  of  chloroform  are  added  until  the  pow- 
der is  completely  exhausted,  and  the  chloroform  subsequently  dis- 
placed by  means  of  water.  The  chloroform  used  must  be  as  free 
;as  possible  from  alcohol,  otherwise  the  extracted  matter  will  contain 
considerable  amounts  of  podophylloquercetin  and  podo])hyllinic  acid, 
which  render  the  purification  of  the  podophyllotoxin  difficult.  For 
the  same  reason  the  podophyllum  is  extracted  at  ordinary  tempera- 
tures and  not  upon  the  water-bath.  From  the  collected  and  combined 
liquids  the  chloroform  is  distilled  off  until  a  residue  of  a  syrupy  con- 
sistence remains ;  this  is  gradually  added  to  2  volumes  of  pure  absolute 
ether,  or  the  same  portion  of  ether  is  gradually  added  to  the  chloro- 
form residue,  stirring  with  a  glass  rod,  until  by  the  further  addition  of 
ether  a  flocculent  separation  is  no  longer  formed.  Podophyllotoxin 
and  the  fatty  substances  dissolve  in  the  ether-chloroform,  while  the 
