Am-Jour.Pharm.j        AcUve  Coustituents  of  PodophylUn.  Ill 
zome;  as  the  starting  pointy  however,  podophyllotoxin  should  be 
selected. 
In  the  preparation  of  podophyllotoxin  for  obtaining  picropodophyl- 
lin,  the  former  does  not  require  to  be  freed  from  the  podophyllinic 
acid.  From  every  variety  of  officinal  podophyllin  the  podophyllotoxin 
must  be  extracted  in  the  same  way  as  from  the  podophyllum  rhizome; 
the  concentrated  chloroformic  solution,  however,  does  not  require  to 
be  mixed  with  petroleum  ether,  and  this  relatively  expensive  operation 
can  be  avoided  by  evaporating  the  chloroformic  solution  upon  the 
water-bath  until  the  chloroform  has  completely  volatilized,  and  subse- 
quently boiling  the  residual  brownish-yellow  mass  with  fresh  portions 
of  petroleum  ether  until  greenish  fatty  matters  are  no  longer  taken  up 
and  the  entire  mass  is  converted  into  a  granular  powder. 
During  the  boiling  the  mass  must  be  continually  actively  mixed 
with  the  petroleum  ether^  in  order  that  it  become  thoroughly  pene- 
trated. After  the  removal  of  the  fatty  matters,  it  swells  up,  and 
finally  falls  to  a  powder,  which  consists  of  impure  podophyllotoxin 
with  the  adhering  impurities. 
In  order  to  prepare  the  crystallized  podophyllotoxin,  the  obtained 
powder  is  dissolved  in  a  small  amount  of  alcohol,  and  a  con- 
siderable excess  of  freshly  slaked  lime  added  ;  the  mixture  is  then 
evaporated  on  the  water-bath  to  dryness,  with  constant  stirring.  The 
granular  powder  obtained  by  evaporation  with  lime  is  finely  pow- 
dered, brought  into  a  glass  flask,  and  boiled  on  the  water-bath  with 
absolute  or  at  least  90  per  cent,  alcohol.  The  alcohol  thus  takes 
up  the  picropodophyllin  from  the  lime  mixture,  and  the  solution  is 
brought  upon  a  previously  warmed  filter.  The  funnel  with  the  filter 
must  of  necessity  be  heated  with  warm  water,  otherwise  a  considerable 
amount  of  podophyllotoxin  will  crystallize  out  on  the  filter,  become 
mixed  with  the  lime  powder,  and  retard  the  filtration.  From  the 
sufficiently  concentrated  alcoholic  liquid  the  picropodophyllin  crystal- 
lizes out  upon  cooling  in  long,  snowy,  silk-like  crystals.  The  lime 
powder  remaining  on  the  filter  is  boiled  with  fresh  portions  of  alcohol 
as  long  as  anything  is  taken  up  and  upon  cooling  needle-shaped 
crystals  continue  to  be  separated.  The  picropodophyllin  crystals  are 
collected  on  a  filter,  and  washed  with  50  per  cent,  alcohol  to  which 
a  little  of  an  aqueous  or  alcoholic  solution  of  ammonia  has  been  added; 
the  60  per  cent,  alcohol  dissolves  the  foreign  colored  admixtures, 
while  the  ammonia  removes  the  last  traces  of  the  picropodopliyllinic 
8 
