138 "Report of Bepaetment of Ani^mal Industry of the 



The octa-silver phytate, CeHieOsvPeAgs, is precipitated as a white 

 amorphous powder by alcohol from an aqueous solution of phytic 

 acid containing twelve equivalents of silver nitrate. 



The hepta-silver phj-tate, C6Hi7027P6Ag7, results when the dilute 

 nitric-acid solution of the above octa-silver phytate is precipitated 

 with alcohol. 



Since various attempts to synthesize phji^ic acid or to prepare a 

 hexa-phosphoric acid ester of inosite by acting on inosite with phos- 

 phoric acid onh' lead to the formation of the tetra-phosphoric acid 

 ester of inosite ^ it seemed of interest to determine what products 

 would be formed when acting on inosite with pyrophosphoric acid. 

 If phytin were a complex pyrophosphoric acid compound of inosite 

 as suggested by Starkenstein - it appeared not impossible to syn- 

 thesize it from these constituents. Such a synthesis would be of 

 considerable theoretical and scientific value in connection with the 

 chemistry of phytin and would also furnish an additional proof of the 

 presence of pyrophosphoric acid compounds in nature. 



Several futile efforts were made in this direction but it was found 

 that the reactions tried only lead to pyrophosphoric acid esters of 

 inosite. These esters are very easily formed but their purification 

 is very difficult. 



When acting on dry inosite (1 mol.) with dry pyrophosphoric acid 

 (3 mol. or sufficient to form phytic acid) at a temperature of 200°- 

 220° a new and stable ester is formed. On analysis, results were 

 obtained corresponding to a di-pyrophosphoric acid ester of inosite, 

 a compound isomeric with the tetra-phosphoric acid ester described 

 in a former paper. 



Attempts to isolate the reaction product by the method described 

 for the tetra-phosphoric ester, ^ that is, by precipitating as a barium 

 salt with alcohol, in the presence of hj'drochloric acid, failed at first 

 because barium pyrophosphate is equally insoluble in acidified dilute 

 alcohol as barium ph}i:ate, for instance, or the pyrophosphoric acid 

 esters. Various other salts were tried with negative results; the 

 pyrophosphate invariably would be precipitated at the same time. 



As is well knowTi, pyrophosphoric acid when boiled ■v\ith dilute 

 mineral acids is very easily transformed into orthophosphoric acid. 

 The isolation of the new ester was made possible by taking advantage 

 of this property. 



In the last paper "* it was reported that phytin, when drj^ and free 

 from mineral acids, is stable; that drying at 115° C. caused no appre- 

 ciable decomposition and that no inosite could be isolated from 

 100 gms. of phytin after drying to constant weight at this temperature, 



1 Anderson, loc. cit. 



* Biochem. Ztschr. 30: 56. 

 ^ Anderson, loc. cit. 



* Ibid, loc. cit. 



