480 
Glycyrrhizin  in  Licorice  Root. 
( Am.  Jour.  Pharm. 
I      July,  1921. 
3-V-. 
4. . . . 
5... 
2. . . . 
1 . . . . 
9-38 
7.24 
4.66 
1-52 
0.52 
o-33 
0.44 
9.11 
6.72 
4.11 
2.39 
0.45 
o-33 
1. 12 
10.35 
6.17 
0.12  and  for  control. 
0.15 
3.21 
1.89 
0.78 
23.69%  23.23% 
22.67% 
After  I  had  thus  proved  that  the  powdered  root  had  been  ex- 
hausted with  50  per  cent,  alcohol,  I  digested  it  for  three  hours  on 
the  water  bath,  with  alcohol  of  the  same  strength.  The  evaporated 
filtrate  gave  no  glycyrrhizin  reaction.  It  really  seems  then  that  the 
total  glycyrrhizin  is  removed  by  the  cold  alcoholic  extraction.  House- 
man gives  no  further  information  as  to  how  the  extract  is  to  be 
worked  up.  It  is,  however,  clear  that  the  extract,  evaporated  to  dry- 
ness, is  to  be  treated  by  the  method  which  he  gives  under  licorice  ex- 
tract. I  so  proceeded,  and  obtained  in  the  residues  given  above,  6.4 
per  cent.,  6.1  per  cent,  and  6.8  per  cent,  glycyrrhizic  acid. 
Houseman  only  reports,  as  I  have  stated  above,  on  the  progress 
of  his  own  researches,  in  which  he  used  100  g.  of  each  kind  of 
root,  and  does  not  state  the  further  examination  of  the  alcoholic  ex- 
tract of  the  glycyrrhizinate.  The  extract  from  10  g.  of  root,  amount- 
ing to  about  2.5  g.,  cannot  well  be  dissolved  in  10  cc.  hot  water.  I 
needed  20  cc.  and  used  accordingly  twice  as  much  alcohol.  The 
glycyrrhizin  obtained  was  of  a  light  brown  color  and  therefore  con- 
siderably purer  than  that  obtained  by  any  other  methods  for  licorice 
extract.  The  impurities,  which  give  to  the  glycyrrhizin  from  the 
licorice  extract  a  nearly  black  color,  appear  in  the  extract  only 
through  the  method  of  manufacture.  The  control  of  Houseman's 
method  shows  its  suitability.  It  seems  to  give  quantitative  yields  of 
the  glycyrrhizic  acid,  with  a  high  degree  of  purity  of  the  latter.  Sub- 
stituting an  extraction  with  alcohol  for  percolation  with  water  must 
be  regarded  as  a  considerable  improvement. 
It  might  be  recommended  to  use  absolute  alcohol  for  the  first 
extraction,  and  add  a  few  drops  of  ammonia  to  the  total  quantity 
used  for  extraction,  in  order  to  fix  the  free  glycyrrhizic  acid,  and 
make  it  insoluble  in  absolute  alcohol. 
