474 



D. O. JORDAN 



TABLE V 



Some Examples of Molecular Weights op Various Pentose Nucleic Acids 



h. Pentose Nucleic Acids 



The molecular weights which have been recorded for pentose nucleic 

 acids vary from 1.31 X 10* to 2.9 X 10^ according to the source, method 

 of preparation, and method of measurement. The low value of 1.31 X 10* 

 was obtained by Myrback and Jorpes^^ and for many years was the main 

 evidence in support of the tetranucleotide hypothesis, now long discarded. 

 The experimental method employed by Myrback and Jorpes has been 

 criticized by Fletcher,^* who considered, on a re-evaluation of their data, 

 that the molecular weight of the sample was near 6 X 10*, which although 



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76 I. Jungner, Acta Physiol. Scand. 20, Suppl. 69, 1 (1950). 



7' G. Jungner, Trans. Faraday Soc. 46, 792 (1950) ; G. Jungner and I. Jungner, Acta 



Chem. Scand. 6, 1391 (1952); G. Junger, Acta Chem. Scand. 6, 1405 (1952). 

 " K. Myrback and E. Jorpes, Z. phijsiol. Chem. 237, 159 (1935). 

 7* W. E. Fletcher, On the Structure of Nucleic Acids, Doctoral thesis, London Univ., 



London, England, 1948. 

 79 H. S. Loring, J. Biol. Chem. 128, Sci. Proc. 33, 61 (1939). 

 *" F. G. Fischer, I. Bottger, and H. Lehmann-Echternacht, Z. physiol. Chem. 271, 



246 (1941). 

 81 W. E. Fletcher, J. M. Gulland, D. O. Jordan, and H. E. Dibben, /. Chem. Soc. 



1944, 30. 

 " I. Watanabe and K. Iso, J. Chem. Soc. Japan 71, 280 (1950). 

 " I. Watanabe and K. Iso, J. Am. Chem. Soc. 72, 4836 (1950). 

 8* G. Jungner and L.-G. Allg^n, Acta Chem. Scand. 4, 1300 (1950). 

 8' L. Delcambe and V. Desreux, Bull. soc. chim. Beiges 59, 521 (1950). 

 86a E. Volkin and C. E. Carter, J. Am. Chem. Soc. 73, 1516 (1951). 

 86b E. L. Grinnan and W. A. Mosher, J. Biol. Chem. 191, 719 (1951). 

 860 E. R. M. Kay and A. L. Dounce, J. Am. Chem. Soc. 75, 4041 (1953). 

 8« S. S. Cohen and W. M. Stanley, J. Biol. Chem. 144, 589 (1942). 



