On Yeast Nucleic Acid. 



89 



ness and finally by the complete break-down of the grafts, while 

 autodermic grafting later was entirely successful. 



Tests in other cases were made by applying a single isograft 

 alongside of autografts. In the cases thus far known to have at 

 the time growing cancer, the isografts did not live. In other 

 cases, we have not yet the final data. Histologic studies showed 

 degeneration of the deeper cellular elements of the isografts. Nine 

 cases were thus observed. 



On yeast nucleic acid. 



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



[From the Department of Chemistry of the Laboratories of the 

 Rockefeller Institute for Medical Research^ 



On hydrolysis of yeast nucleic acid the following components 

 had been maintained : adenin, guanin, cytosin, uracil, dribose and 

 phosphoric acid. On the basis of this knowledge and on the basis 

 of the results of the elementary composition of the acid, the com- 

 position of the yeast nucleic acid was expressed schematically in the 

 following manner : 



That part of this assumption which tended to give expression to 

 the manner in which the purin bases were linked in the molecule 

 was confirmed by the finding of two ribosides, namely, guanosin 

 and adenosin. However, there are known some properties of the 

 nucleic acid which cannot be well interpreted by assuming for the 

 pyrimidin bases the same manner of union as for the purin bases. 



A new substance was obtained on hydrolysis of the yeast 

 nucleic acid of the composition of C 5 H 9 0 4 C 4 H 4 N 3 0. On hydrol- 

 ysis the substance yields cytosin, but no ribose. It contains in its 

 molecule one free amino group and two hydroxyls. The follow- 

 ing crystalline derivatives of the substance were obtained : picrate 



55 (465) 



0 



0 



o 



0 



