550 OXIDATION FERMENTS 



may be freed from adnexed catalases and oxygenases by 

 preparatory treatment with pyrogallol. 37 



Probably C. Oppenheimer 38 has fully and correctly 

 grasped the present status of the question, when he states as 

 his opinion that for the present at least we must accept the 

 active, thermolabile peroxidases as ferments. "For the 

 results indicating that various mixtures of salts of man- 

 ganese and of iron act qualitatively in precisely the same 

 way, in themselves prove nothing against an enzymic nature, 

 as similar analogies are met in case of almost all ferments. 

 Against this view, above all should be recognized the fact 

 that we can demonstrate very active peroxidases which do 

 not contain manganese or iron.^ True oxidase activity really 

 has nothing essential to do with these salts, even though sug- 

 gestions to the contrary perhaps exist. In the living tissue 

 provisions would seem to be made that biological catalysing 

 agents, ferments, should do what under other conditions 

 inorganic catalysers are able to do." 



Indophenoloxidases. Attention should be directed 

 briefly to several other types of oxidases, of which frequent 

 mention is made in literature. Among these first are indo- 

 phenoloxidases. The synthesis of indophenol from para- 

 phenylendiamine and a-naphthol, 



NH Z 



/ 



C 6 H 4 (NH 2 ) 2 + 6 10 H 7 (OH) + O 2 = C 6 H/ 



X N = CioH 6 O + 2H 2 O, 



was first made use of by Ehrlich in 1885 in his classical study 

 of physiological oxygen requirements of the economy. From 

 the standpoint of the oxidizing ferments Eohmann and Spit- 

 zer, and after them a great number of others, 39 have em- 

 ployed the reaction, partly for histochemical purposes. Ee- 

 cently Vernon 40 has endeavored to perfect a quantitative 



37 A. Kasanski (Moscow), Biochem. Zeitschr., 89, 64, 1911. 



** C. Oppenheimer, 1. c., p. 351. 



89 J. Pohl, Rosell, Abelous and BiarnSs and others. Literature: J. H. 

 Kastle, 1. c., pp. 100-103; R. Spanjer-Herford (Braunschweig), Virchow's 

 Arch., 205, 276, 1911; W. H. Schultze (Gottingen), Ziegler's Beitr., 45, 127, 

 1909; F. Winkler, 1. c. 



