AbaSBE  fmrm' }  Aconine  and  Conversion  into  Aconitine.  209 
ON  THE  FORMATION  AND  PROPERTIES  OF  ACONINE 
AND  ITS  CONVERSION  INTO  ACONITINE.1 
By  Professor  Dunstan  and  Dr..  F.  W.  Passmore. 
From  the  Research  Laboratory  of  the  Pharmaceutical  Society. 
Owing  to  the  uncertainty  which  exists  with  reference  to  the  pro- 
ducts of  the  hydrolysis  of  aconitine,  the  authors  have  investigated 
the  subject,  starting  with  a  pure  alkaloid.  Wright  and  Luff  have 
stated  that  when  aconitine  undergoes  hydrolysis  the  sole  products 
are  aconine  and  benzoic  acid.  More  recently  Dragendorff  and 
Jurgens  have  asserted  that  the  hydrolysis  occurs  in  two  stages.  In 
the  first  stage  there  are  formed  benzoic  acid  and  an  alkaloid  iden- 
tical with  the  picraconitine  once  isolated  by  Wright  and  Luff  from 
the  roots  of  supposed  Aconitum  Napellus.  In  the  second  stage  the 
picraconitine  is  hydrolyzed '  into  benzoic  acid,  methyl  alcohol  and 
aconine,  which  is  the  final  product  of  the  change. 
The  authors  have  carefully  studied  the  process  of  hydrolysis  by 
heating  pure  aconitine  with  water  in  closed  tubes  at  1500,  but  have 
been  unable  to  obtain  at  any  stage  either  picraconitine  or  methyl 
alcohol.  The  alkaloid  extracted  from  the  solution  by  ether  was  a 
mixture  of  aconine  with  unaltered  aconitine.  With  pure  aconitine 
the  reaction  occurs  precisely  in  accordance  with  the  equation 
C^NO,,  +  H20=C26H41NO„  +  C  H602 
Having  accumulated  in  these  experiments  a  few  grains  of  aco- 
nine, the  authors  proceeded  to  examine  its  properties  when  in  a 
pure  state.  Up  to  the  present  time  neither  it  nor  its  salts  have  been 
obtained  in  a  crystalline  state.  The  base,  even  when  quite  pure, 
cannot  apparently  be  crystallized  ;  all  attempts  to  induce  crystal- 
lization having  failed.  The  authors  have,  however,  succeeded  in 
crystallizing  several  of  the  salts,  viz.:  the  hydrochloride,  hydrobro- 
mide,  sulphate  and  nitrate.  All  these  salts  are  very  soluble  in 
water ;  the  hydrochloride  being  the  least  soluble  is  the  easiest  to 
crystallize.  This  salt  is  best  purified  by  crystallization  from  a  mix- 
ture of  alcohol  and  ether.  When  dried  at  100°  it  melts  at  175-5° 
(corr.).  The  crystals  deposited  from  alcohol  have  the  composition 
C26H41NOn,HCl,2H20.  When  dried  at  1000,  they  still  retain  1 
H20,  which  is,  however,  lost  at  1200.    The  aqueous  solution  is  laevo- 
1  The  substance  of  a  paper  communicated  to  the  Chemical  Society  on  March 
3,  1892  ;  reprinted  from  Phar.  Jour,  and  Trans.,  March  5,  p.  729. 
