358 Report of the Department of Chemistry of the 



Deducting the barium found, allowing for hydrogen and water, 

 and calculating to the free acid these results became: 



C = 20.88; H = 4.11 ; P = 19.16 per ct. 



This is approximately the composition of inosite diphosphate, 

 C 6 H 14 O 12 P 2 = 340. 

 Calculated: C = 21.17; H = 4.11; P = 18.23 per ct. 



That these substances, separated from the partially decomposed 

 phytic acid, are inosite esters of phosphoric acid and not conden- 

 sation or other decomposition products is evident from the fact 

 that on complete cleavage inosite is obtained. Unfortunately the 

 amount of each of the above substances was too small to permit of 

 examination in this direction except the last one, viz., the water- 

 soluble product precipitated by alcohol and which analyzed for 

 inosite diphosphate. The remainder (0.94 grams dry substance) 

 was hydrolyzed with dilute sulphuric acid in a sealed tube at 150°- 

 160° for about 2\ hours and the inosite isolated in the usual way. 

 The amount of inosite obtained was 0.28 gram or about 88 per ct. 

 of the theory. The substance gave the reaction of Scherer and 

 melted at 222° (uncorrected) which leaves no doubt that it was pure 

 inosite. 



It is evident that all of the barium precipitates described above 

 are mixtures. It could hardly be expected that a complete sepa- 

 ration into pure chemical compounds of the salts of these inosite 

 esters could be effected by the method used. The analytical results, 

 however, show that it is possible to isolate from partially decomposed 

 phytic acid certain substances approximating in composition various 

 phosphoric acid esters of inosite which on complete cleavage yield 

 inosite just as does phytic acid itself. This fact, we believe, supports 

 the view previously expressed that phytic acid suffers a gradual 

 and partial decomposition, i. e., molecules of phosphoric acid are 

 eliminated one by one. We believe also that these facts taken in 

 connection with the formation of inosite from phytic acid on mere 

 drying at 105° must be considered as a strong support of the theory 

 that phytic acid is inosite hexaphosphate and not some complex 

 compound as previously held. 



ATTEMPT TO PREPARE A METHYL ESTER OF PHYTIC ACID. 



The silver salt previously described as hepta-silver phytate 12 was 

 used. Of this salt, 5.4 grams were suspended in 100 cubic centimeters 

 of absolute methyl alcohol and 4 grams of methyl iodide (a little over 

 the required amount) were added and the mixture shaken for several 

 hours, the flask being protected from the light. At the end of this 

 time the white silver phytate had changed into the yellow silver iodide. 



"Journ. Biol. Chem. 12 : 107, 1912, and N. Y. Exp. Sta. Tech. Bull. 21, 1912. 



