142 



OXIDATION-REDUCTION POTENTIALS 



at pH 7 between — 0-10 volt and 4-0-15 volt. These limits of potential are similar, as 

 mentioned in the previous section, to those found by von Jancso as being necessary 

 for the interference of various oxidation-reduction potential dyes with the bactericidal 

 effects of organic arsenic and antimony compounds. It is possible that poising of the 

 oxidation-reduction potential between these limits has some significant effect on 

 bacterial inhibitions. 



TABLE 27 

 Bacteriostatic Activity and Oxidation-Reduction Potentials of Quinones 



ANTIMALARIALS, PALUDRINE, ANTRYCIDE 



One of the earliest successful chemotherapeutic agents, quinine has been 

 succeeded in turn by a quinoline compound, plasmoquine, an acridine, mepacrine 

 and then paludrine, for malarial treatment and suppression. 



Paludrine (Curd and Rose, 1946) is a guanidine derivative, 



ClCeH^.NH.C ( : NH) NH.C ( : NH) NH.CHlCHa)^. 



Originally search was being made for active pyrimidine ring derivatives, but the 

 •open chain biguanide proved to be the most successful compound. For the ridding of 

 the body of the last malarial parasites in benign tertiary malaria another drug, penta- 

 quine, a derivative of methoxy quinoline is promising well. As in most chemo- 

 therapeutic problems the search is for an agent with the maximal therapeutic effect 

 and the minimum toxicity to the host. Much interest attaches to the trials pro- 

 ceeding at present of antrycide, which is a pyrimidyl quinaldine : — 



