experimental part. The organic phosphoric acids which remained were 

 obtained as amorphous barium salts. It was impossible to isolate 

 any unchanged barium phytate. It is evident, then, that all of the 

 phytin had been partially hydrolyzed. 



The above amorphous substance appeared to consist mainly of 

 barium inosite triphosphate, but probably mixed with some barium 

 inosite diphosphate. Owing to the difficulty by separating these com- 

 pounds, their isolation was not attempted. 



Among the soluble substances which had been formed we were 

 able to isolate and identify inosite monophosphoric acid, a substance 

 which we have previously isolated from wheat bran. In addition to 

 this, the solution also contained some free inosite which was isolated 

 by means of its lead compound. 



The action of this enzyme phytase upon phytin appears to proceed 

 in several stages. Only a portion of the phytin is completely decom- 

 posed into inosite and phosphoric acid, but all of the phytin is par- 

 tially hydrolyzed with formation of certain lower phosphoric acid 

 esters of inosite ; viz., inosite tri-, di- and monophosphoric acid and 

 inorganic phosphoric acid. The formation of these intermediate pro- 

 ducts is possible only through the destruction or inhibition of the 

 enzyme before the hydrolysis is complete. The reason for this inhibi- 

 tion is not clear but it may be due to the excess of phosphoric acid 

 which is liberated. 



It is interesting to note, and we call particular attention to the 

 fact, that the' organic phosphoric acids which remain as intermediate 

 products of the action of the enzyme upon phytin; viz., inosite tri- 

 phosphoric acid and inosite monophosphoric acid, are identical with 

 the substances which we have isolated previously from wheat bran 

 after it has been digested in 0.2 per cent, hydrochloric acid. 



EXPERIMENTAL PART 



Commercial phytin, 100 grams, was dissolved in 500 c.c. of water 

 and filtered from the insoluble matter which weighed 3.5 grams when 

 dried at 100°. The pale yellow solution was treated with 38 grams of 

 oxalic acid dissolved in about 250 cc. of water. The calcium oxalate 

 was filtered off, washed and dried. It weighed 48 grams. The solution 

 was diluted to 6000 cc. with water and was then found to contain 40 

 grams of phosphorus pentoxide. To it were added 800 cc. of an 

 aqueous extract of wheat bran which contained 2.2 grams of P 2 O s . 

 The solution was kept under toluol at a temperature of 37°. No hydroly- 

 sis occurred in a week. This was evidently due to the strong acid reaction 

 of the solution: It was nearly neutralized with ammonia and 735 cc. of 

 bran extract containing 1.53 grams of P 2 O s were added. It was again 

 kept at a temperature of 37° under toluol. In 9 days one-half of the total 



44 



