56 



Scientific Proceedings (31). 



24 (362) 



Further studies on the constitution of inosinic acid. 



By W. A. JACOBS and P. A. LEVENE. 



\^From the Rockefeller Institute for Medical Research^ 

 In a former article ^ on the constitution of the inosinic acid ob- 

 tained from beef extract, we have demonstrated that by acid hydro- 

 lysis there is formed an intermediate product, a pentose phosphoric 

 acid, which we isolated as a well crystallized barium salt. From 

 the fact that this body showed strong reducing properties, it is 

 evident that the aldehyde group is free, and the phosphoric acid is 

 bound, ester-like, on one of the hydroxyl groups of the pentose. 

 As the inosinic acid itself does not reduce Fehling's solution, it is 

 at once obvious that the hypoxanthin contained in its molecule 

 must be bound as in a glucoside on the aldehyde group. We also 

 mentioned that upon alkaline hydrolysis we were able to isolate a 

 small quantity of a silver compound of a purin-pentose complex 

 which gave all the qualitative tests for such a body. 



Meanwhile it came to our notice that Haiser and Wenzel ^ had 

 obtained a compound of hypoxanthin and a pentose from karnin to 

 which they gave the name inosin. We have succeeded, by heating 

 the barium salt of inosinic acid in water solution in a sealed tube 

 at 125°— 130°, in obtaining a mixture from which we have isolated 

 a substance which in all respects corresponds with Haiser and 

 Wenzel's inosin. 



From this substance we obtained a levorotatory pentosazone. 

 Furfurol distillation yielded the phloroglucid required by a pentose. 



1 Levene and Jacobs: Berichte d. deut. chem. Gesell. , 41, 2703 (1908). 

 'Haiser and Wenzel: Monatshefte fiir Chemie, 29, 157 (1908). 



