Am.  Jour.  Pharm. 
July,  1921. 
Glycyrrhizin  in  Licorice  Root. 
479 
rhizin  in  the  extract.  After  having  removed  the  resins  and  bitter 
substances  by  this  method,  he  extracts  with  50  per  cent,  alcohol, 
and  claims  that  he  obtains  the  glycyrrhizin  quantitatively.  In  spite  of 
this,  I  am  not  sure  whether  Houseman  claims  a  quantitative  yield 
for  his  method.  Some  parts  of  his  research  seem  to  speak  against  it. 
For  instance,  the  root  is  only  to  be  used  after  careful  picking.  But 
for  quantitative  methods,  one  should  demand  that  not  only  selected 
pieces  can  be  examined,  but  also  average  samples.  When  further, 
Houseman  finds  0.5  per  cent,  glycyrrhizin  in  the  last  alcoholic  ex- 
tract, and  considers  the  root  thereby  exhausted,  without  putting  on  a 
control  experiment,  I  fail  to  follow  him  on  this  point. 
I  will  now  go  through  his  method  and  communicate  the  results 
of  my  control  of  it. 
Before  use,  the  root  is  to  be  dried  in  a  vacuum  desiccator.  The 
root  I  used  contained  9.2  per  cent,  of  moisture.  After  standing  five 
days  over  sulphuric  acid  in  a  vacuum  desiccator,  the  moisture  con- 
tent was  redued  to  3.8  per  cent.  Ten  g.  of  this  roughly  powdered 
root  was  extracted  four  times  with  100  cc.  portions  of  95  per  cent, 
alcohol.  I  allowed  each  extract  to  stand  24  hours  with  frequent 
shaking.  Houseman  does  not  state  how  much  alcohol  is  obtained 
each  time.  I  evaporated  the  400  cc.  of  extract,  and  obtained  a  con- 
siderable residue  of  a  brown  yellow  color.  The  portion  of  this  residue 
which  is  soluble  in  warm  water,  gave  after  cooling,  and  acidifying 
with  sulphuric  acid,  a  very  trifling,  flocculent  precipitate,  and  there- 
fore contained  very  small  traces  of  salts  of  glycyrrhizin,  and  prob- 
ably also  traces  of  free  glycyrrhizic  acid.  The  portion  of  the  root 
which  had  been  freed  from  resins  and  bitter  substances  is  now  treated 
with  50  per  cent,  alcohol.  Here  again  Houseman  states  no  quanti- 
ties. * 
I  extracted  six  times,  with  50  cc.  each,  of  50  per  cent,  alcohol 
(Houseman  prescribes  only  five  times).  In  order  to  establish  the 
quantity  of  extract  removed  each  time,  and  thereby  the  progressive 
extraction  of  the  root,  I  evaporated  the  extract  each  time,  in  the 
same  tared  crucible.  I  so  obtained  the  amount  of  extract  from  each 
succeeding  extraction.  After  standing  for  a  half  a  day,  the  extract 
was  poured  off  and  another  50  cc.  of  alcohol  added.  The  extraction 
with  the  two  strengths  of  alcohol  thus  lasted  a  total  of  seven  days. 
With  50  per  cent,  alcohol  I  obtained  the  following  quantities 
after  evaporation: 
