CARL L. A. SCHMIDT AND G. F. NORMAN 685 



mentioned that the ammonia, which is formed as a result of the oxida- 

 tion of the amino-acid, is probably not free but is combined with the 

 ketonic acid. 



Neuberg (10) studied the mechanism of the reaction which takes 

 place when solutions of certain amino-acids to which uranium salts 

 have been added are exposed to sunlight. In addition to oxidative 

 deamination, he found that CO2 was split off from the carboxyl 

 group yielding an aldehyde, the reaction being similar to that which 

 takes place when an amino-acid is oxidized with H2O2. When serine 

 is exposed to sunlight or is oxidized with H2O2, glycol aldehyde is 

 formed according to the reaction: 



COOH 



I CHO 



CHNH2 + 0=1 + CO2 + NH, 



I CH2OH 



CH2OH 



This reaction like the one discussed previously is universal, and fails 

 to explain the specific reducing action of tyrosine and tryptophane. 



It is a well recognized fact that benzene and a large number of 

 aromatic substances of varied types undergo substitution of the hydro- 

 gen atoms in the nucleus to a more or less marked extent, and in vitro this 

 reaction can be brought about by ozone, H2O2, and by photochemical 

 action (11). We have attempted to test the possible application of 

 this reaction to the subject of eosin hemolysis. Suspensions of washed 

 red cells were treated respectively with H2O2 (saline solution of the 

 neutralized product), H2O2 plus a small amount of catalase, and H2O2 

 plus platinum black. In each instance the oxyhemoglobin was con- 

 verted into methemoglobin, but hemolysis did not take place. On 

 saturating red cells with ozone a similar result was obtained. Tubes 

 containing red cells to which platinum black and colloidal palladium 

 were added, showed no hemolysis after exposure for a half hour to 

 sunlight. Evidently hemolysis cannot be brought about with the aid 

 of H2O2. The fact that substances which contain either the hydroxy- 

 phenyl ring which apparently facilitates the introduction into the 

 nucleus of other OH groups, or the indole ring which is easily oxidized 

 to indoxyl and then to indigo blue (Abderhalden (12) has noted that 

 tryptophane and adrenalin are sensitive to light), can afford protection 



