RECENT WORK IN AGRICULTURAL SCIENCE 



AGRICULTURAL CHEMISTRY— A6R0TECHNY. 



Phytin and phytic acid, G. Clarke (Jour. Chem. Soc. [Loiidon], 105 (1914), 

 Ko. 617, pp. 535-5.'f5). — The pbytin studied in tliis worlc was obtained from the 

 seeds of Indian field mustards, a mixture of Brassica juncea and B. campestris. 

 Dilute acetic acid was preferred to very dilute hydrochloric acid for the ex- 

 traction because it was found that the extracts obtained by the latter were 

 difRcult to handle. The free acid liberated from air-dried phytin of homo- 

 geneous composition consisted of a mixture of approximately equal quantities 

 of an organic phosphoric acid (phytic acid) and phosphoric acid. 



"A solution of the ammonium salt of the organic phosphoric acid, prepared 

 from a pure strychnin salt [melting point, 203 to 204°i C, imcorrected]. gave 

 no precipitate on warming to 60° with a nitric acid solution of ammonium 

 molybdate, and only a vei'y slight one on remaining at that temperature for 

 several hours. 



"An explanation of the behavior of phytin is that it is not simply a salt 

 of an inositolphosphoric acid, but a complex substance, possibly a complex 

 calcium-magnesium salt of an inositolphosphoric acid and phosphoric acid, 

 and, on removing the bases, yields the two acids. The fact that the composi- 

 tion of pure phytin, prepared as described, corresponds with no calcium- 

 magnesium salt of a simple acid ester of inositol and phosphoric acid gave sup- 

 port to this view. The strychnin salt of the oi'ganic phosiihoric acid, isolated 

 from the mixture of acids obtained from phytin, on the other hand, gave results 

 on analysis in agreement with salts of simple inositolphosphoric acids." 



The acid tribarium phytate preparation of Anderson (E. S. R., 27, p. 406), 

 prepared by precipitation from a 0.5 per cent hydrochloric acid solution by the 

 addition of an equal volume of alcohol, " was probably one of the purest deriva- 

 tives of phytic acid hitherto isolated, but it seemed not impossible from the 

 methods of preparation that the salt as well as the acid prepared from it 

 might contain some phosphoric acid." 



"The phytin prepared [in these investigations] was a snow-white, amorphous 

 powder, resembling in properties the substance described by Schulze and Win- 

 terstein. It contained carbon, hydrogen, phosphorus, calcium, and magnesium, 

 but no trace of nitrogen could be detected. It was insoluble in hot and cold 

 water, readily soluble in very dilute mineral acids, and soluble In cold, but 

 sparingly so in hot dilute acetic acid. It was precipitated from a cold 8 per 

 cent acetic acid solution on boiling, completely redissolviug when allowed to 

 cool. . . . 



" It was somewhat difficult to obtain phytin in an anhydrous condition. After 

 heating for several hours at 110° in a vacuum over phosphoric oxid it still con- 

 tinued to lose weight. When heated under similar conditions at 180° for five 

 hours it became constant in weight, and remained so after prolonged heating 

 for many hours. The anhydrous substance, drie<l at 180° and dissolved in dilute 

 acetic acid, was precipitated again unchanged by boiling." 



16 



