- 
  
  
 - 
  
  Alexander Fleming noticed a mold growing on a culture plate, and identified the substance as bacterial growth.
 - 
  
  
 - 
  
  A biochemical research team made by Howard Florey produced stable penicillin
 - 
  
  
 - 
  
  Dorothy Hodgkin corrected the chemical formula of penicillin
 - 
  
  
 - 
  
  Ernst Brandl and Hans Margreiter developed the first acid-stable penicillin for oral administration.
 - 
  
  John Sheehan developed the first chemical synthesis of penicillin
 -