ISOLATION AND COMPOSITION OF DEOXYPENTOSE NUCLEIC ACIDS 



357 



TABLE X 



Purine and Pyrimidine Contents of Sodium Deoxypentose 



Nucleates of Various Animals (from Birds Downward) 



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 Separate analyses indicate a content in 5-metliylcytosine corresponding to 6.6% of the cytosine value. 



References 



" M. M. Daly et at.. J. Gen. I'hyswl. 33, 497 (1950); chromatography of free bases on starch columns. 



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

 " H. Fraenkel-Conrat and E. D. Ducay, Biochem. J. 49, XXXIX (1951). 



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

 ' G. R. Wyatt, Biochem. J. 48, 584 (1951). 

 ■^ E. Chargaff et al.. J. Biol. Chem. 192, 223 (1951). 

 B E. Chargaff el al. , J. Biol. Chem. 195, 155 (1952). 



not astonishing that some of the analyses are not of desirable quality, but 

 the trend is evident. It shows a very wide range of composition differences 

 going from the extreme AT type (yeast) to the extreme GC type (tubercle 

 bacilli). It is remarkable that all specimens from acid-fast bacteria (Nos. 



