QUININE ESTERS OF PHENYLARSINIC ACID DERIVATIVES. 



By K. J. Oechslin. 

 (From the Chemical Division, Bureau of Science, Manila, P. I.) 



The results obtained in tlie treatment of surra with arsenophenyl- 

 glycin by Strong and Teague, of the Biological Laboratory of this 

 Bureau/ were so favorable that much hope was offered ultimately for a 

 satisfactory cure of this infection. However, it was desirable that a less 

 toxic preparation than arsenophenylglycin for the animal and one equally 

 toxic for the parasite be secured. The following paper is the outcome 

 of some work done in connection with Doctor Teague in the testing of the 

 most promising drugs so far known for surra, which finally led to the 

 chemical preparation of the quinine esters. After preparing several 

 bodies which did not contain arsenic and after a discussion of the field 

 of work with Doctors Freer and Strong, I took up the preparation of 

 quinine derivatives and compounds which led finally to the preparation 

 of a number of quinine esters of phenylarsinic acid derivatives. 



The best drugs which have possibilities as a specific against surra 

 known at the present time were found by Strong and Teague to be 

 arsenophenylglycin and atoxyl. However, these are still far from being 

 satisfactory, since the dose which is required to effect a cure is so close 

 to the lethal one that too great a percentage of the animals treated with 

 them succumb to arsenic poisoning. 



Earlier investigators had paid pronounced attention to combinations 

 of drugs. Amongst them tlie combined application of the derivatives 

 of arsenic and salts of arsenious acid with alkaloids such as strychnine or 

 quinine can be mentioned, but no better results were obtained from them.^ 

 These earlier experiments led to the plan of combining arsenic derivatives 

 with alkaloids in such a way that the combinations would not be so easily 

 split as would be the case with salts, such as, for instance, quinine arsenate 

 which had found previous application. Thus, the combined action on 

 the living cells of those two physiologically widely different substances is 

 insured. Quinine itself has a pronounced action on trypanosomata, 

 although this is considerably less than that of arsenic, and therefore my 



^This Journal, Sec. B (1910), 5, 29. 



'Uhlenhut, Arl. a. d. kais. Gsndhtsmte. (1909), 29, 403. 



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