Am.  Jour.  Pharm. 
May,  1888. 
Substitutes  for  Chrysai'ohin. 
26r 
ON  THERAPEUTIC  SUBSTITUTES  FOR  CHRYSAROBIX/' 
By  C.  Liebermann. 
In  1878  it  was  shown  by  me  and  Seidler  (Am.  Jour.  Phar.,  1879, 
p.  80),  that  the  active  principle  of  Goa  powder  is  not  chrysophanic 
acid,  but  chrj'sarobin,  in  which  the  quinone- group  of  chrysophanic 
acid  is  partly  reduced,  in  consequence  of  which  chrysarobin  combines 
readily  with  oxygen,  particularly  when  in  alkaline  solution,  a  behavior 
which  is  also  observed  with  an  alkaline  solution  of  pyrogallic  acid. 
At  that  time  it  was  already  pointed  out  that  the  remedial  eifects  of 
Goa  powder  were  probably  not  due  to  the  chrysophanic  acid  produced 
from  chrysarobin  by  oxidation  ;  but  most  likely  to  the  reducing  action 
of  the  latter,  to  its  strong  affinity  for  oxygen.  The  effects  of  pure 
chrysophanic  acid  do  not  appear  to  have  been  studied,  but  its  congener 
alizarin  was,  in  1878,  shown  by  Jarisch  to  be  of  no  value  in  psoriasis^ 
while  pyrogallol  has  a  very  decided  effect.  Jarisch  was  led  to  the  use 
of  the  latter  on  account  of  its  constitution,  it  being  a  polyatomic  phe~ 
nol;  but  he  acknowledges  the  probability  of  its  efficacy  being  mainly 
due  to  the  affinity  for  oxygen. 
The  leuco-substances  of  many  coloring  matters  closely  resemble 
chrysarobin  in  the  property  of  absorbing  oxygen  ;  but  nearest  to  it  in 
their  constitution  are  the  leuco-bodies  of  the  anthraquinone  coloring- 
matters  alizarin,  flavopurpurin,  anthrapurpurin,  anthragallol  and 
others.  Granting  the  correctness  of  my  view,  it  was  to  be  expected 
that  these  leuco-bodies  should  possess  remedial  properties  similar  to 
those  of  chrysarobin.  For  therapeutic  purposes  only  such  deserved  to 
be  considered  which  may  be  readily  prepared  on  a  large  scale,  and 
among  these  alizarin  and  the  two  purpurins  are  obtainable  at  a  rela- 
tively low  price. 
The  reduction  of  these  color-compounds  was  first  effected  by  boiling 
with  glacial  acetic  acid  and  granulated  tin,  with  the  successive  addi- 
tion of  small  quantities  of  fuming  kydrochloric  acid  to  effect  a  brisk 
evolution  of  hydrogen ;  a  light  yellowish  solution  is  finally  obtained, 
which  is  filtered,  boiling  hot,  from  the  tin,  and  then  precipitated  with 
water ;  the  reduction  product  is  collected  upon  a  filter,  well  Avashed 
with  acidulated  water,  freed  from  the  acid  and  dried  upon  earthen 
plates.  This  process  requires  some  experience  to  avoid  resinificatiorL 
of  the  product.    On  this  account  and  because  of  the  high  price  of  the 
1  Abstract  of  a  paper  in  Berichte  d.  d.  Chem.  Ges.,  1888,  p.  447-452.  J.  M.M. 
