In 1935 Domagk1 showed that prontosil2 had a marked protective and therapeutic value in experimental streptococcic infections in mice. This observation has been confirmed by numerous investigators. The drug also has a beneficial effect on similar infections in other animals and in man. Shortly after Domagk's discovery, Tréfouél and his co-workers3 showed that prontosil was broken down in the tissues to triaminobenzene and para-aminobenzene sulfonamide. The latter compound was believed by them to be the effective component of prontosil. Recently numerous derivatives of the drug have been synthesized, but the estimation of the effectiveness of many of them requires further investigation.
The mode of action of sulfanilamide and its derivatives is still the subject of much conjecture. Since prontosil has little or no bactericidal action in vitro. Domagk believed that enhancement of phagocytosis of the streptococci by the leukocytes explained its beneficial effect. Levaditi and Vaisman4
SAKO W, DWAN PF, PLATOU ES. SULFANILAMIDE AND SERUM IN THE TREATMENT AND PROPHYLAXIS OF SCARLET FEVER. JAMA. 1938;111(11):995–997. doi:10.1001/jama.1938.02790370015004