Am.  Jour.  Pharm. 
Jan.,  1885. 
Polygonum  Hydi'opiper. 
21 
A  CHEMICAL  EXAMINATION  OF  POLYGONUM 
HYDROPIPER. 
By  Henry  Trimble  and  Herman  J.  Schuchard. 
,[A  contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of 
Pharmacy.] 
From  recent  reports  of  the  medicinal  activity  of  this  drug  and  from 
the  absence  of  a  complete  analysis  of  it,  we  were  induced  to  undertake 
an  examination  with  a  view,  primarily,  of  determining  the  nature  of 
the  pungent  principle.  The  drug  was  collected  for  us  in  the  vicinity 
of  Philadelphia,  during  the  past  summer,  by,  a  botanist  thoroughly 
familiar  with  the  requirements  of  the  case,  so  there  can  be  no  doubt 
about  the  species  of  Polygonum  employed  in  the  following  analysis. 
About  50  grams  of  the  tops  and  leaves,  free  from  the  larger  stems, 
were  powdered  and  the  whole  passed  through  a  No.  80  sieve ;  of  this 
2')  grams  were  taken,  and  the  scheme  recommended  in  DragendorfP's 
Plant  Analysis  followed  as  closely  as  the  peculiarities  of  the  case  would 
admit. 
Petroleum  spirit,  with  a  boiling  point  below  45 °C.,  extracted  2* 7 
per  cent,  of  a  material  which  proved  to  be  a  wax,  melting  at  48 °C., 
soluble  in  absolute  alcohol,  ether  and  chloroform,  and  saponifying  with 
alcoholic  potash.    No  volatile  or  fixed  oils  were  found. 
The  drug,  after  extraction  with  petroleum  spirit,  was  dried  and 
exhausted  with  absolute  ether,  which  extracted  1*54  per  cent.,  a  very 
small  portion  of  which  was  soluble  in  water,  the  remainder  was  solu- 
ble in  chloroform,  benzol  and  absolute  alcohol;  a  concentrated  solution 
in  the  last  solvent,  when  poured  into  water  caused  a  turbidity  due  to 
resin  ;  from  these  and  some  other  tests,  we  were  led  to  believe  that  the 
ether-soluble  portion  consisted  of  resin  and  chlorophyll. 
The  original  drug  after  the  ether  treatment  was  dried  and  exhausted 
with  absolute  alcohol,  by  which  we  obtained  5*14  per  cent,  of  solid 
matter.  2*27  per  cent,  of  this  was  soluble  in  water;  this  aqueous 
solution  contained  tannin.  When  made  alkaline  and  treated  succes- 
sively with  petroleum  spirit,  benzol  and  chloroform,  then  acidified  and 
similarly  treated,  ho  crystalline  principle  was  obtained.  The  portion 
of  the  alcoholic  extract  insoluble  in  water  proved  to  be  an  acid  resin. 
The  alcoholic  solution  contained  the  pungent  principle,  but  on  heating 
it  disappeared. 
The  remainder  of  the  original  drug  yielded  to  water  7*22  per  cent. 
