ON A NEW FUNCTION OF THE CATALYZER CALLED 



" PEROXIDASE " AND ON THE BIOCHEMICAL 



TRANSFORMATION OF ORCIN TO ORCEIN^ 



JULES WOLFF 



In a recent publication I have described the influence which 

 peroxidase exerts on certain phenols in the presence of various salts 

 and alkalies.^ When dissolved in a weak sodium carbonate Solu- 

 tion freely exposed to the air, orcin, for example, fixes from four 

 to five times more oxygen in the presence of peroxidase than in its 

 absence. In this note I wish to call attention to the fact that perox- 

 idase has other powers than the fixation of atmospheric oxygen. 



In determining the combined influence of ammonia and perox- 

 idase upon aqueous Solutions of orcin, I have studied conditions 

 which favor the transformation of orcin^ into orcein, the beautiful 

 coloring matter which is one of the principal constituents of com- 

 mercial orseille. 



My observations are interesting from many points of view. 

 They show that (i) if a 2 per cent. Solution of orcin is exposed 

 to the air in a thin layer and subjected to the influence of different 

 proportions of ammonia, orcein is not formed even after a month 

 under such conditions, but, instead, there is produced a substance 

 which imparts a brownish-red color to the liquid. (2) If, how- 

 ever, a portion of the same Solution is put in a narrow tube, so that 

 the reaction takes place in a deeper layer, and the surface of con- 

 tact with air is limited (other conditions being equal), one observes 

 a very slow but regulär formation of orcein. (3) If (everything 

 eise being equal) one repeats the first experiment (i), but adds to 

 the ammoniacal Solution of orcin a suitable quantity of peroxidase, 

 orcein fails to appear, just as in the first experiment. (4) If, how- 



* Translated from the author's manuscript, in French, by Dr. J. J. Bronfen- 

 brenner. [Ed.] 



''Wolff: Comptes rendus, 1912, clv, p. 618. 



'Orcin has been the subject of interesting work by Robiquet, Dumas, Liebig, 

 and Laurent and Gerhardt. 



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