164 



J. BADDILEY 



the same rate during alkaline hydrolysisi«« and adenosine-5'-phosphate 

 gives adenosine when dephosphorylated by alkaline phosphatase. ^^i ^he 

 presence of an unsubstituted m-l,2-glycol structure in adenosine-5'-phos- 

 phate is indicated by the ready formation of its boric acid complex.'^^ 



f 



N 



— 



OH OH 

 I I 

 •- CH • CH • CH • CH • CHs • OPO^Hj 



NHj 



. N 



XXII 



Muscle adenylic acid 



c. Guanosine-5' -phosphate {XXIII) 



It is now known that guanosine-5'-phosphate is produced during enzymic 

 hydrolysis of ribonucleic acid.'^* Although it is converted into guanosine 

 through the action of a 5'-phosphatase, it is different from the isomeric 

 guanylic acids a and h. The structure of this nucleotide was established by 

 direct comparison with synthetic guanosine-5'-phosphate. 



-0- 



•OPO3H, 



N 



OH OH 

 I I 

 L-CH-CH-CH-CH-CHs 



OH 



XXIII 

 G uanosine-5'-phosphate 



d. Cytidine-S' -phosphate (XXIV) 



Enzymic hydrolysates of ribonucleic acid may also contain cytidine-5'- 

 phosphate.125 Similar structural considerations apply to this nucleotide as 



-O- 



0< 



N 



OH OH 

 I I 

 •-CH • CH • CH • CH • CH2 • OPO3H2 



N. 



NH2 



XXIV 



Cytidine-5'-phosphate 



IS" G. Embden and G. Schmidt, Z. physiol. Chem. 181, 130 (1929). 

 1" J. M. Gulland and E. R. Holiday, /. Chem. Soc. 1936, 765. 

 1" R. Klimek and J. K. Parnas, Biochem. Z. 292, 356 (1937). 



