August 27, 1920] 



SCIENCE 



203 



oxidation of organic substances. The occur- 

 rence of catalase is so general in plant and 

 animal tissues that its existence certainly 

 must have a significance. Loew conceived the 

 idea that peroxides are formed in the cells in 

 the process of respiration, and that the cata- 

 lase saves the protoplasm from being injured 

 by these peroxides by decomposing them as 

 fast as they are being formed. Usher and 

 Priestly^ have shown that in plants at any 

 rate hydrogen peroxide is actually one of the 

 substances formed under the action of light 

 and, if not immediately destroyed by catalase, 

 will bleach the chlorophyl and thus interfere 

 with the photosynthetic reaction. In the la.st 

 few years the work of Appleman, Zaleski and 

 Rosenberg, Loevenhart and Kastle, Alvarez 

 and Starkweather, McArthur and notably of 

 Burge have drawn attention to the probable 

 function of catalase, as an index of metabolic 

 activity. Our interest in catalase originated 

 with this fundamental problem of the relation 

 of catalase to tissue metabolism. It may be 

 mentioned that since our research has been in 

 progress a number of papers appeared by 

 Becht,^ Stehle,° Eeimann and Becher^ which 

 not merely challenge the interpretation which 

 Burge and others place on catalases, but also 

 their experimental findings. 



The observations of which this is a pre- 

 liminary report, although not bearing directly 

 upon the fundamental problem of the catalase 

 function, throw nevertheless interesting light 

 on the subject. The literature contains many 

 instances of inorganic substances, such as 

 colloidal platinum and several others which 

 possess remarkable catalytic power, and bring 

 about reactions characteristic of enzymes. 

 Thus Sjolleman'' found that colloidal manga- 

 nous oxide gives all the typical reactions for 

 oxidases. Again "Wolffs showed that certain 



3 Usher ajid Priestly, Proc. Soy. Soc. London, 

 7TB, 369, 1906. 



4 Beeht, Am. J. Physiol, 48, 171-191, 1919. 



5 Stehle, J. Biol. Chem., 39, 403, 1919. 



« Reimaim and Becker, Am. J. Physiol., 50, 54, 

 1919. 



7 SjoUeman, Chem. WeeUad, 6, 287-294, 1909. 



8 Wolff, C. r. Ac. Sc, 146, 142-144, 781-783, 1908. 



iron salts can play the part of peroxidases, 

 while Bredig's^ "inorganic ferment" — a col- 

 loidal platinum — is capable of decomposing 

 hydrogen peroxide as vigorously as catalase. 

 There is, however, no record of organic sub- 

 stances simulating a biological process. We 

 have discovered a group of aromatic hydro- 

 carbons and their derivatives which give the 

 typical catalase reaction. Such substances 

 may undoubtedly help to throw light on the 

 chemical structure and characteristics of the 

 enzyme itself. 



Our numerous experiments which we will 

 report in detail later arose' from the acci- 

 dental observation that an enzyme prepara- 

 tion preserved with toluol had acquired a re- 

 markably increased capacity for decomposing 

 hydrogen peroxide. It was at that time also 

 that a paper appeared by Euler and Blix^" on 

 yeast catalase in which these authors state 

 that the catalase is activated by several sub- 

 stances, toluol among them. The idea of an 

 activation of the enzyme by toluol seemed en- 

 tirely improbable from our experience, because 

 we found that even such minute quantities of 

 toluol as 0.05 or 0.1 ccm. can decompose hy- 

 drogen peroxide. We undertook therefore to 

 examine a number of related organic com- 

 pounds in the hope of finding whether this 

 non specific catalase reaction is in any way 

 associated with the chemical structure of the 

 organic catalysts. Starting with benzene we 

 studied a number of its homologues and some 

 of its derivatives. Benzene was found to re- 

 act most vigorously, 0.2 ccm. liberating about 

 20 ccm. of oxygen from hydrogen peroxide in 

 a manner so closely resembling the effect of an 

 active enzjrme preparation that one could not 

 tell the difference imless informed as to the 

 material used in the test. 



The aromatic hydrocarbons of the benzene 

 group form a series according to the number 

 of methyl radicles attached to the ring with a 

 gradually decreasing power to decompose hy- 

 drogen peroxide, thus: 



Benzene > Toluol > Xylol > Mesitylene 



» Bredig, ' ' Anorganisehe Fennente, ' ' 1901. 

 10 Euler und Blix, Zischr. physiol. Chem., 105, 

 83-114, 1919. 



