ANTIBACTERIAL AGENTS 



203 



largely discarded in favour of sulphonamides and penicillin. 

 !nHo HpNL i L iNHg 



h^nI 



CH3 CI 



Acriflavin Proflavin 



Triphenylmethane dyes : mixtures of tetra-, penta-, and 

 hexa-methyl-tri-amino-tri-plienyl-metliane dyes are effective 

 against some Gram-positive bacteria, but are also somewhat 

 toxic to the host. They are commonly used in burn dressings, 

 where their coagulant properties are of use. 



,CH, 



/ 



CH 



3\ 



/^N'~CH3 



HpN 



o-^ 



HHCl 



OxX^ 



^3\ / 



J 



CH, 



OH 



CRYSTAL VIOLET 

 (CARBINOL BASE) 



p-ROSANILINE 



The relative effects of some of these antibacterial substances 

 when tested in vitro against a typically Gram-positive Staph, 

 aureus and Gram-negative Esch. coli are given in Table XVI. 



TABLE XVI 



Limiting Effective Molar Concentration of some 

 Antibacterial Agents 



All these values are subject to wide variations with the strain of the 

 test organism and with the nature of the growth medium. 



