356 



ERWIN CHARGAFF 



TABLE IX 



Selection of Data on Purine and Pyrimidine Contents of Sodium 



Deoxypentose Nucleate Preparations from Different 



Tissues of Several Mammalian Genera 



Proportions in moles of nitrogenous constituent per 100 g. -atoms of P 



in hydrolysate, corrected for a 100% recovery.* 



* Compare footnotes in Table VII. 



t In addition, 1.1 mole % of S-methylcytosine was found, 

 t In addition, 1.0 mole % of 5-methylcytosine was found. 



References 



" S. G. Laland et al., J. Chem. Soc. 1952, 3224. 



* G. R. Wyatt, Bicchem. J. 48, 584 (1951). 



'E. Chargaff and R. Lipshitz, J. Am. Chem. Soc. 75, 3658 (1953). 



M. M. Daly et al., J. Gen. Phyaiol. 33, 497 (1950); chromatography of free bases on starch colymns. 

 ' E. ChargafT el al., Nature 165, 756 (1950); correction as for Preparations 1 and 2 in Table VII. 

 ' R. O. Hurst etal., J. Biol. Chem. 204, 847 (1953); ion-exchange chromatography of mononucleotides. 



ate of wheat germ has been mentioned before. Data on the purine and py- 

 rimidine composition of different preparations of. this nucleic acid analyzed 

 in four laboratories are presented in Table XI ; the agreement is satisfactory. 

 As has been mentioned before, little information on other plant nucleic 

 acids is available. 



What is known about the composition of microbial deoxypentose nucleic 

 acids and some related compounds from rickettsiae and viruses is collected 

 in Table XII. In view of the difficulty of securing sufficient material it is 



