Paul Ehrlich studied arsenic compounds for their anti-bacterial properties, and in 1909 invented Salvarsan, which was applied for the successful treatment of syphilis. This strategy was followed by other researchers to find active compounds in combating infectious diseases.
Treponema pallidum bacteria
Accordingly, Prontosil, the first sulfa drug, formerly used as a textile dye, was discovered in 1935, as chemists searched for an antibacterial drug that might cure the previously deadly streptococcal infection, a common cause for chronic pneumonia. Its discovery was important enough for German biochemist Gerhard Domagk to receive the 1939 Nobel Prize in medicine.
In 1938, a British research group showed that it was sulphanilamide that was the actual active antibacterial agent in Prontosil. Many products were later created from this agent, including sulphapyridine (1938) that was dramatically successful in reducing the mortality rate of lobar pneumonia in the 1940s, and saved the life of millions in military and civil sectors. Sulphanilamide only lost its importance with the discovery of pennicilin. Today, sulphanilamides are mainly used for reducing high blood-sugar level and utilized in diuretics.