KUCLEIC ACIDS 147 



THE PARTIAL DECOMPOSITION PRODUCTS OF THYMUS 



NUCLEIC ACID 



Levf ne and Mandel (a) (11)08) prepared an indefinite substance from 

 thymus nucleic acid which produced phosphoric acid, levulinie acid and 

 thymine. They conclude that the substance is thyinino-hexa-nueleotide. 



Levene and Jacobs (i) (1013) prepared a substance from thyrmis 

 nucleic acid that forms guanine and levulinic acid. It is possibly guanine- 

 hexa-nucleoside. 



If these two substances, one a nucleoside and the other a nucleotide, 

 indicate that thymus nucleic acid is constructed throughout upon nucleo- 

 sides and micleotides, then the later work of Leveuc and Jacobs (j) (1012) 

 suggests the structure of thymus nucleic acid. Their argument is based 

 upon the assumed structures of three compounds which they obtained by 

 the mild hydrolysis of thymus nucleic acid with sulphuric acid. 



1. Hexa-thymidine di-phosphoric acid 



2. Hexa-eytidine di-phosphoric acid ^J 



3. llexa-cytosine-thymine-di-nucleotide 1 " 



HO\ 

 0-P OH 

 O/ 

 H0\ | 



O^P_0 . C H 5 . C 5 II,X 2 2 

 HO/ 



Thyiuulinc Di-phospliorif Aeiil 



HO\ 



0-PO . C U II 9 3 . C 5 II C X.,0 2 

 HO/ | 



O 

 H0\ | 



0-P . C C II :; : C 4 II 4 X 3 

 HO/ 



Tliymine-CytosineDi-nueiooride 



HO\ 



o-p o . o u n 9 o 3 . c 4 H 4 x 3 o 



HO/ I 



o\ 



0=P OH 

 HO/ 



Cytidine Di-phosplioric Acid 



1 In the nomenclature of the decomposition products of nucleic acids the prefixes 

 ''perita" and "liexa" liave reference to the carbohydrate groups. *'Hexa" means "from 

 thymus nucleic acid": "penta." means "from yeast nucleic acid." 



