170 



J. BADDILEY 



PO3H2 



-J-0 — 



P03H, 



o< 



O OH 



CH-CH-CH-CH-CH2-0H 



U 



04- 



OH 

 I I 

 i-CH-CH-CH-CH-CHj-OH 



N, 

 NH2 



XXXI 



Cytidine-3'-phosphate 



NH2 



XXX 



Cytidine-2'-phosphate 



i. Uridylic Acids a and b 



The substance known as uridylic acid was isolated, along with cytidylic 

 acid, from ribonucleic acid hydrolysates.^*^' 188-192 Ljj^g cytidylic acid, it can 

 be hydrolyzed to the nucleoside and phosphoric acid. Also, dihydrouridylic 

 acid yields uracil, ribose, and phosphoric acid on acid hydrolysis. Uridylic 

 acid may be separated into the two isomers, uridylic acid a and uridylic 

 acid 6^^° and it has been shown that cytidylic acid h is deaminated under 

 alkaline conditions to uridylic acid h}^^ Since the conditions of deamination 

 do not allow phosphate migration, it is concluded that uridylic acid a 

 corresponds to cytidylic acid a with respect to the position of the phosphate 

 group, and uridylic acid b corresponds to cytidylic acid b. Uridylic acids a 

 and b are probably the 2'- and 3'-phosphates of uridine, respectively 

 (XXXII, XXXIII). 



PO3H2 



-fo— 



P03H2 



OH 



'-CH-CH-CH-CH-CH2-0H 



o=r 



OH 



xxxn 



Uridine-2'-phosphate 



-0- 



OH 



LCH • CH • CH • CH • CH; • OH 



i 



o=r 



OH 



xxxni 



Uridine-3'-phosphate 



j. Cyclic Phosphates 



Among the products of the action of ribonuclease on ribonucleic acid are 

 pyrimidine nucleotides which differ from any of those described so far.^^®' "^ 



'»5 L. F. Cavalieri, /. Am. Chem. Soc. 74, 5804 (1952). 



ISO J. J. Fox and L. F. Cavalieri, Federation Proc. 12, 204 (1953). 



1" R. J. C. Harris, S. F. D. Orr, E. M. F. Roe, and J. F. Thomas, J. Chem. Soc. 1953, 



489. 

 192 S. J. Thannhauser, Z. physiol. Chem. 100, 121 (1917). 

 1" D. M. Brown, C. A. Dekker, and A. R. Todd, J. Chem. Soc. 1952, 2715. 



