H. C. HAMPTON AND L. G. M. BAAS-BECKING 647 



Oxidase and Peroxidase. 



Oxidase. — Pyrocatechine is quickly oxidized in the presence of 

 ground Ulva. 10 gm. of grindings, 200 mg. of pyrocatechine, and 25 

 cc. of water gave in 20 hours in the manometer a negative pressure 

 of 2 mm. 5 gm. of grindings, 300 mg. of pyrocatechine, and 25 cc. 

 of water gave in 20 hours in the manometer a negative pressure of 

 3 mm. These are indications that Ulva contains an oxidase. Reed 

 found in Ulva an oxidase which acted on guaiacol, pyrogallol, hydro- 

 chinon, paraphenylendiamine, and a-naphtol. 



To determine whether the reaction of the pyrocatechine was due 

 to the action of the plant we prepared two test-tubes; A, 100 mg. of 

 pyrocatechine and 10 cc. of distilled water, and, B, 100 mg. of pyro- 

 catechine, 5 cc. of distilled water, and 5 cc. of Ulva extract. B gave 

 a strong red color after 1 hour; A remained light yellow. 



We were not able to get an appreciable reaction with guaiacol, 

 paraphenylendiamine, or a-naphtol, or a combination of the last two 

 substances. 



100 mg. of pyrocatechine were oxidized in 17 hours by 1 cc.of extract 

 to the same color as 0.2 cc. of 0.1 n potassium permanganate would 

 give it. 



100 mg. of pyrogallol were oxidized in 17 hours by 1 cc. of extract 

 to the same color as 1.75 cc. of potassium permanganate would give 

 it (dark brown). A control experiment without enzyme gave a light 

 color (0.25 cc. of potassium permanganate). 



100 mg. of guaiacol or 100 mg. of phenol were not oxidized in 17 

 hours. 



In conclusion we may say that Ulva contains a rather strong 

 oxidase, active on pyrocatechine and pyrogallol, inactive on guaiacol, 

 phenol, paraphenylendiamine, and -\- a-naphtol. 



Peroxidase. — We tried two peroxidase tests. One, the luminescence 

 of pyrogallol -f- H2O2 (Harvey) failed under the different circumstances. 

 The other, the action of plant juice on ring compounds -\- H2O2 

 succeeded only in a faintly alkaline medium. We were able to obtain 

 the same reactions without enzyme in alkaline solution. Therefore, 

 we do not feel justified in concluding that a peroxidase is present. 

 For example 



