274  Extraction  of  Hydrastine  and  Berberine.  {Am'^yr\gj9arm' 
few  drops  of  sodium  hydroxide  solution  and  i  Cc.  of  acetone  and 
after  standing  some  hours  diluted  with  an  equal  bulk  of  water,  good 
crystals  of  berberine-acetone  will  be  deposited  within  24  hours  if 
0.0010  Gm.  of  the  alkaloid  is  present. 
A  microchemical  method  of  detecting  berberine  has  been  de- 
scribed by  Bauer.2  A  section  of  the  plant  tissue  is  floated  in  a  few 
drops  of  water  on  a  microscope  slide,  allowed  to  macerate  for  a 
few  seconds,  warmed  with  one  or  two  drops  of  sodium  hydroxide 
solution  (10  per  cent.)  and  treated  with  four  or  five  drops  of  acetone 
and  covered  with  a  micro-cover  glass.  The  growths  of  characteristic 
crystals  of  berberine-acetone  is  observed  under  the  microscope  in 
some  cases  in  5  minutes,  while  in  others  several  hours  are  required. 
Estimation. — Gravimetric  method  of  Gordin.  The  berberine  in 
an  aqueous-alcoholic  solution  is  precipitated  with  excess  of  a  10  per 
cent,  solution  of  potassium  iodide,  the  precipitated  iodide  washed 
with  a  two  per  cent,  solution  of  KI  and  transfered  with  a  little 
water  into  a  flask.  After  heating  to  6o°-yo°  acetone  is  added  to 
the  extent  of  one-third  the  volume  of  the  water  and  the  mixture 
shaken  for  10  minutes.  Five  Cc.  of  a  10  per  cent,  solution  of 
sodium  hydroxide  are  then  added  and  the  liquid  shaken  (heating 
to  50°-6o°  if  necessary)  until  the  yellow  hydro-iodide  has  disap- 
peared. After  cooling,  the  solution  is  diluted  with  water  to  three 
times  its  bulk  and  allowed  to  stand  over  night.  The  berberine-ace- 
tone is  filtered  off,  dried  first  under  reduced  pressure  and  then  at  105  0 
and  weighed.  One  Gm.  of  the  acetone  compound  corresponds  with 
0.853  Gm-  of  berberine.  To  correct  for  the  berberine  acetone  dis- 
solved in  the  mother  liquer  0.0000273  is  added  per  Cc. 
Berberine  Hydrochloride. — By  the  above  mentioned  method  of 
manufacturing  berberine,  the  hydrochloride  of  the  alkaloid  is  ob- 
tained. This  salt  is  the  easiest  obtainable  and  is  very  stable.  It  is 
not  as  soluble  as  the  sulphate  but  as  effective,  and  is  readily  soluble 
in  boiling  water.  It  is  almost  insoluble  in  alcohol  or  dilute  hydro- 
chloric acid  and  is  with  difficulty  decomposed  by  bases.  Silver- 
oxide  readily  decomposes  it  in  solution.  By  prolonged  exposure  at 
ioo°  the  color  changes  permanently  to  an  orange  color  and  the  salt 
becomes  readily  soluble  in  water  with  a  red  color.  This  does  not 
contain  much  if  any  free  chlorine. 
Tests. — The  mixture  of  the  salt  with  KI  changes  to  a  graphite 
color  when  treated  with  a  drop  of  hydrochloric  acid  and  then  to  a 
2  Pharm.  Zeit.,  1908,  53,  618. 
