104 



Scientific Proceedings (105). 



Chart i. 



"Apparently o-aminophenol is to a comparatively small 

 extent converted into the isomeric, highly toxic para compound, 

 while the remainder is conjugated either with H 2 S0 4 with the 

 introduction of an acetyl group, or with urea with the subsequent 

 elimination of 2 N H 3 radicals." 



Sieburg also studied the behavior of para-arsenobenzoic acid 

 and of 3-amino-arsenobenzoic acid in the body of the calf and 

 concludes that in all cases a cleavage of the toxophoric— As = As — 

 linking in 'arseno' compounds occurs in the living organism, 

 whereby not only is the toxicity reduced, but transformation 

 takes place into compounds which are more soluble in water and 

 less easily soluble in other media. The characteristic effects are 

 due to the small proportion of the substance which escapes oxida- 

 tion to the arsinic acids, and to the subsequent liberation of the 

 As 2 0 3 and As 2 0 5 . M 



Sieburg's discovery of conjugated phenol derivatives resulting 

 from the metabolism of salvarsan as well as our independent 

 investigations on the causes of the reactions following intravenous 

 injections of arsphenamine and neo-arsphenamine 1 led us to 

 direct our attention to the mechanism of detoxication which 

 the body possesses, — the power of rendering innocuous various 

 aromatic toxic substances by conjugation with sulphuric acid, 

 ^-glucuronic acid, urea, glycocoll, bile acids, etc. It seemed 

 plausible to venture the hypothesis that in those patients in whom 

 severe reactions are observed within a few hours or days after 

 intravenous injection of arsphenamine or neo-arsphenamine, 



1 Schamberg, J. F., Kolmer, J. A., Raiziss, G. W., and Weiss, Charles, Arch. 

 Dermal. &* Syph., 1920, I, 235-256. 



