Am.  Jour.  Pharm. 
JuDe,  1901. 
Developments  in  Organic  Compounds. 
267 
physiologic  action  depend  largely  upon  the  relative  position  of  the 
replacing  groups. 
In  general,  substitution  lessens  the  toxic  characters  of  phenols, 
provided  the  entering  groups  are  not  toxic — for  example,  salicylic 
acid,  gallic  acid,  sulfocarbolic  acid. 
The  hydroxyl  group  is  intimately  associated  with  the  toxic 
action  of  morphin,  which,  through  its  narcotic  characters,  differs 
from  all  other  opium  alkaloids,  its  action  being  chiefly  upon  the 
nerve  centers  of  the  brain.  Upon  closing  these  OH  groups  through 
the  replacement  of  one  or  both  of  the  hydrogens  by  alkyl  or  acid 
radicals,  the  narcotic  characters  disappear,  where,  on  the  other 
hand,  a  spinal  excitant  (tetanic  action)  is  developed,  increasing  with 
the  number  of  alkyl  radicals  introduced.  Thus  codein  produces 
like  morphin  (but  in  lesser  degree)  narcosis  followed  by  an  elevated 
reflex  excitability  which,  if  the  dose  is  sufficiently  large,  develops 
tetanic  convulsions.  Dionin  (ethyl  ether  of  morphin)  is  more  active 
than  codein.  Other  members  of  this  class  are  Peronin  (benzyl 
morphin)  and  Heroin  (di-acetyl  morphin).  These  substances,  while 
less  active  for  relieving  pain,  exert  a  sedative  effect  on  the  unstriped 
muscles  of  the  bronchi  and  reduce  the  disposition  to  cough,  hence 
are  of  value  in  phthisis,  bronchitis,  asthma,  etc. 
/OH 
Morphin  C17H17. 
^NO 
OH 
OH 
Codein  C17H17 
Lionin  C17H17 
Peronin  C17H17. 
Heroin  C17H17. 
NO  .  OCTL 
OH 
^NO 
,OH 
NO 
,0 
OC2H5 
OC6H5CH2 
-  CH3CON. 
NO  .  O  —  CHqCO 
Methyl  morphin. 
Ethyl  morphin. 
Benzyl  morphin. 
Di-acetyl-  morphin . 
The  most  toxic  alkaloid  of  opium  is  Thebain,  which,  accord- 
ing to  Stockmann,  aside  from  its  narcotic  action  in  small  doses,  is 
identical  in  tetanic  effect  to  strychnin. 
