Am.  Tour.  Pharm. 
May,  191 8. 
Urinary  Antisepsis. 
353 
phthalein  gives  a  soluble  compound  (phenolphthalein  sulphonic  acid), 
the  sodium  salt  of  which  is  excreted  almost  as  rapidly  as  is  phenol- 
sulphonephthalein.  The  similarity  of  names,  however,  between  this 
compound  and  phenolsulphonephthalein  should  not  give  the  impres- 
sion that  the  two  are  the  same.  They  differ  in  composition,  struc- 
ture and  method  of  preparation.  Since  the  sulphonation  of  phenol- 
phthalein causes  its  rapid  excretion,  the  conclusion  might  be  drawn 
that  the  sulphonic  acid  group  is  essential  for  rapid  elimination ;  but 
this  theory  is  upset  by  the  action  of  the  following  group  of  com- 
pounds. The  sodium  salt  of  sulphonated  phenolphthalein  has  no 
antiseptic  value. 
Conclusion. — The  phthaleins  give  no  promise  of  value  as  urinary 
antiseptics. 
Compounds  of  this  class  are  characterized  by  the  fact  that  the 
two  phenol  groups  are  linked  together  by  an  oxygen  atom,  as  il- 
lustrated by  the  structural  formula  given  in  Fig.  4.  It  will  be  seen 
that  this  formula  differs  from  that  of  phenolphthalein  only  in  the 
presence  of  an  oxygen  atom,  although  the  two  compounds  possess 
divergent  biologic  properties.  The  compounds  of  this  class  investi- 
gated were  fluorescein  (resorcinphthalein),  sulphonefluorescein  (re- 
sorcinsulphonephthalein),  orcinsulphonephthalein,  rhodamin  and  re- 
sorcinsaccharein.  All  of  these  compounds  in  solution  are  greenish 
and  extremely  fluorescent,  and  without  exception  they  are  excreted 
by  the  kidney  with  a  rapidity  as  great  as  that  of  phenolsulphone- 
phthalein, if  not  greater ;  the  average  rate  of  excretion  for  the  group 
being  70  per  cent,  in  one  hour.  Since  these  compounds  are  quite 
different  chemically,  but  have  one  characteristic  in  common  (the 
oxygen  linking  two  phenol  groups),  and  since  they  all  show  great 
"  renal  affinity,"  it  is  reasonable  to  assume  that  we  have  here  a  defi- 
nite relationship  between  chemical  structure  and  physiologic  action. 
Xanthones. 
