460 CHEMISTRY OF THE PROTEIDS CHAP. 



guanylic acid which differs from the one above in containing one 

 additional glycerine-pentose radical : 



OH OH 



\/ 



C 5 H 4 N 5 -0-P-0-C 3 H 5 (OH)C 5 H 9 5 



O 



C 5 H 4 N 5 -0-P-0-C 3 H 5 (OH)C 5 H 9 5 





 \/ 

 p C 3 H 5 (OH)C 5 H 9 5 







C 5 H 4 N 5 -0-P-0 C 3 H 5 (OH)C 5 H 9 5 



OH OH 

 a-guanylic acid. 



This new acid, being the higher compound, Bang calls the 

 a-guanylic acid, while the substance he obtained previously he now 

 calls the /3-guanylic acid. By splitting off further glycerine-pentose 

 radicals, y, 8, and e-guanylic acid will be formed. 



The a-guanylic acid contains 29'46 per cent guanin andj 34'07 

 per cent pentose. When it is boiled with alkalies it becomes con- 

 verted into /2-guanylic acid. 



Guanidin has been observed by Kutscher and Otori l amongst the 

 products of auto-digested pancreas, and as guanidin is also found 

 amongst the hydrolytic products of pseudo-mucin (Otori) the authors 

 incline to the view that guanidin is derived from arginin and not from 

 nucleic acids. 



Levene's 2 statement that uracil is found in auto-digested pancreas 

 has not been confirmed by Kutscher and Lohmann. 3 



The pentose occurring in the nucleo-proteid is, according to 

 Neuberg, 4 Z-xylose. 



1 Fr. Kutscher and Otori, ZentrdLU. /. Physiol 18. 248 (1904). 



2 Levene, Zeitschr. f. physiol. Chem. 37- 527 (1903). 



3 Kutscher and Lohmann, ibid. 44. 385 (1905). 



4 C. Neuberg, Ber. d. deutsch. chem. Ges. 35. II. 1467 (1902). 



