﻿548 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  Studies 
  of 
  the 
  physical 
  and 
  chemical 
  properties 
  of 
  the 
  substance 
  also 
  

   resulted 
  in 
  lack 
  of 
  agreement. 
  

  

  The 
  reasons 
  for 
  most 
  of 
  the 
  observed 
  discrepancies 
  are 
  now 
  appar- 
  

   ent. 
  In 
  recent 
  years 
  it 
  has 
  been 
  demonstrated 
  that 
  several 
  anti- 
  

   bacterial 
  substances, 
  which 
  differ 
  in 
  their 
  mode 
  and 
  specificity 
  of 
  

   action, 
  are 
  produced 
  by 
  Pseudomonas 
  aeruginosa. 
  Furthermore, 
  dif- 
  

   ferent 
  strains 
  of 
  this 
  organism 
  do 
  not 
  behave 
  alike 
  in 
  their 
  elaboration 
  

   of 
  the 
  various 
  compounds 
  and, 
  moreover, 
  for 
  a 
  given 
  strain 
  the 
  pro- 
  

   duction 
  of 
  each 
  of 
  the 
  active 
  agents 
  is 
  influenced 
  by 
  a 
  number 
  of 
  

   environmental 
  factors. 
  The 
  methods 
  of 
  extraction 
  also 
  are 
  of 
  

   importance 
  in 
  determining 
  the 
  composition 
  of 
  the 
  antibacterial 
  

   preparations. 
  

  

  Pyocyanic 
  acid. 
  — 
  In 
  1908 
  it 
  was 
  found 
  that 
  the 
  bactericidal 
  activity 
  

   of 
  pyocyanase, 
  as 
  well 
  as 
  of 
  Pseudomonas 
  aeruginosa 
  cultures, 
  could 
  

   be 
  extracted 
  by 
  various 
  organic 
  solvents. 
  That 
  pyocyanase 
  really 
  was 
  

   an 
  enzyme 
  had 
  already 
  been 
  questioned 
  by 
  a 
  number 
  of 
  investigators 
  

   and 
  this 
  new 
  finding 
  was 
  interpreted 
  as 
  evidence 
  that 
  the 
  active 
  agent 
  

   was 
  a 
  fatlike 
  substance. 
  The 
  extracts 
  were 
  demonstrated 
  to 
  possess 
  

   the 
  ability 
  to 
  dissolve, 
  or 
  lyse, 
  red 
  blood 
  cells, 
  as 
  well 
  as 
  bacteria. 
  

   Several 
  investigators 
  attempted 
  to 
  identify 
  the 
  active 
  compound. 
  In 
  

   1933 
  an 
  active 
  substance 
  which 
  appeared 
  to 
  be 
  a 
  fatty 
  acid 
  was 
  iso- 
  

   lated 
  and 
  named 
  "pyocyanic 
  acid." 
  This 
  compound 
  has 
  not 
  yet 
  been 
  

   identified 
  and 
  its 
  precise 
  chemical 
  structure 
  is 
  unknown. 
  It 
  is 
  quite 
  

   potent 
  against 
  certain 
  bacteria 
  ; 
  complete 
  inhibition 
  of 
  the 
  growth 
  of 
  

   the 
  cholera 
  vibrio 
  is 
  produced 
  by 
  0.001 
  percent, 
  of 
  the 
  anthrax 
  bacillus 
  

   by 
  0.005 
  percent, 
  of 
  staphylococci 
  by 
  0.02 
  percent. 
  Somewhat 
  higher 
  

   concentrations 
  cause 
  lysis. 
  Pyocyanic 
  acid 
  is 
  a 
  surface-active 
  com- 
  

   pound, 
  that 
  is, 
  in 
  aqueous 
  solutions 
  it 
  has 
  the 
  property 
  of 
  accumulating 
  

   at 
  the 
  interface 
  between 
  phases, 
  such 
  as 
  at 
  the 
  water-air 
  boundary, 
  

   and 
  of 
  reducing 
  the 
  surface 
  tension 
  of 
  the 
  water. 
  This 
  property, 
  

   which 
  is 
  characteristic 
  of 
  detergents 
  or 
  cleaning 
  agents 
  such 
  as 
  soap, 
  

   seems 
  to 
  be 
  of 
  importance 
  in 
  its 
  bacteriolytic 
  action, 
  inasmuch 
  as 
  a 
  

   number 
  of 
  other 
  detergents 
  have 
  been 
  found 
  to 
  produce 
  similar 
  

   biological 
  effects. 
  

  

  The 
  purest 
  preparations 
  of 
  pyocyanic 
  acid 
  thus 
  far 
  tested 
  have 
  

   been 
  found 
  to 
  be 
  moderately 
  toxic 
  to 
  mice. 
  No 
  attempt 
  has 
  yet 
  been 
  

   made 
  to 
  use 
  the 
  substance 
  therapeutically. 
  

  

  Pyocyanine. 
  — 
  One 
  of 
  the 
  most 
  obvious 
  characteristics 
  of 
  Pseudo- 
  

   monas 
  aeruginosa 
  is 
  the 
  production 
  of 
  a 
  water-soluble 
  blue 
  pigment. 
  

   As 
  early 
  as 
  1860 
  this 
  pigment 
  had 
  been 
  isolated 
  from 
  blue 
  pus 
  and 
  

   given 
  the 
  name 
  "pyocyanine." 
  Not 
  until 
  1929, 
  however, 
  was 
  its 
  chem- 
  

   ical 
  nature 
  elucidated 
  and 
  its 
  synthesis 
  accomplished 
  in 
  the 
  labora- 
  

   tory 
  ; 
  it 
  was 
  the 
  first 
  natural 
  product 
  demonstrated 
  to 
  belong 
  to 
  a 
  class 
  

   of 
  organic 
  substances 
  known 
  as 
  phenazonium 
  compounds. 
  There 
  is 
  

  

  