158 ANTIBACTERIAL SUBSTANCES FOR TREATMENT OF INFECTIONS 



to be proved active, and was successful in the treatment of pneumococcal, meningo- 

 coccal and gonococcal infections. Sulphathiazole and sulphadiazine were improve- 

 ments particularly in respect of Staph, aureus infection, and as an example of 

 the selectivity that a drug may display it is interesting to note that sulphadiazine 



NH, 



HCl.HaN< >N=N< ^SOgNH^ 



4'-sulphonamido-2 : 4-diaminoazobenzene ; 

 sulphonamido-crysoitdin. (Prontosil.) 



j3-aniinobenzenesulphonamide ; sulphanilamide 



HO.HN^ ^SOg.NHj 



j3-hydroxylaminobenzenesulphonamide 



H2N.CH2/ NsOa.NHg 



^-aminomethylbenzenesulphonamide (Maifanil) 



H,N< >SO,.NH 



\N/ 



2-(p-aminobenzenesulphonamido)-pyridine ; sulpha- 

 pyridine 



S 



H,N<' >SO,NH 



N' 



2-(/»-aminobenzenesulphonamido)-thiazole ; sulpha- 

 thiazole 





\ / \ 



2-(^9-aminobenzeiiesulphonamido)-pyrimidine; 

 sulphadiazine 



NH, 



sulphanilylguanidine ; sulphaguanidine 



H,N< >COOH 



^-amtnobenzoic acid 

 Fig. 27. 



proved to be effective against Friedlander's bacillus, which had hitherto proved 

 insusceptible to sulphonamides. 



Sulphaguanidine is included as an example of a modification designed to be 

 antibacterial, soluble and yet absorbed with difficulty from the alimentary tract ; 

 suitable, that is, for the treatment of infections of the intestinal tract. 



