CHEMISTRY OF NUCLEOSIDES AND NUCLEOTIDES 189 



pure adenylic acid a, uncontaminated with any h isomer. Migration of a 

 phosphate group then cannot have occurred in this synthesis. The di- 

 acetyladenosine must have been 6,5'-diacetyladenosine. It yielded 6,5'- 

 diacetyl-a-tosyladenosine on treatment with p-toluenesulfonyl chloride 

 and methanolysis of this gave a methyl tosyl-D-ribofuranoside. As this 

 gave 3 , 5-dimethylribose after methylation and hydrolysis, it follows that 

 the original tosylated diacetyladenosine was 3',5'-diacetyl-2'-tosylad- 

 enosine, and hence that adenylic acid a is adenosine-2 '-phosphate. 



X-ray crystallographic analysis indicates that adenylic acid b is the 3'- 

 phosphate.-^^ 



Comparison of the infrared spectra of cytidine and deoxycytidine phos- 

 phates strongly suggests that cytidylic acid h is cytidine-3 '-phosphate and 

 hence uridylic acid b is uridine-3 '-phosphate.-^'' 



Hydrolysis of ribonucleic acid with a crude snake venom yields, amongst 

 other products, 2', 5'- and 3 ',5 '-diphosphates of uridine and cytidine.-*^ 



A diphosphate of 5-hydroxymethylcytosine deoxyriboside has been 

 isolated from bacteriophage nucleic acid.^^" 



The synthesis of deoxynucleoside phosphates has now been extended to 

 the preparation of the 3'- and 5 '-phosphates of deoxycytidine. The latter 

 compound is identical with the deoxycytidylic acid obtained by enzymic 

 hydrolysis of deoxyribonucleic acid.'^*^ 



Nucleotide Coenzymes 



Uridine triphosphate^^^ and guanosine triphosphate^^^ have been isolated 

 from commercial ATP and ATP from rabbit muscle, respectively. Uridine 

 triphosphate has been synthesized enzymically from ATP and uridine-5'- 

 phosphate.^^* A tetraphosphate of adenosine is also present in some samples 

 of ATP.2^* All the mono-, di-, and triphosphates of adenosine, guanosine, 

 uridine, and cytidine have been detected in tumor extracts.^^^- -^^ Cytidine- 

 5 '-phosphate and related compounds have been isolated from Lactobacillus 

 arabinosusP'^ 



«88 A. M. Michelson and A. R. Todd, J. Chem. Soc. 1954, 34. 



289 W. E. Cohn and E. Volkin, /. Biol. Chem. 203, 319 (1953). 



290 L. L. Weed and T. A. Courtenay, J. Biol. Chem. 206, 735 (1954). 



"1 S. H. Lipton, S. A. Morell, A. Frieden, and R. M. Bock, J. Am. Chem. Soc. 75, 



5449 (1953). 

 "2 R. Bergkvist and A. Deutsch, Acta Chem. Scand. 7, 1307, (1953). 

 2" A. Munch-Petersen, H. M. Kalckar, E. Cutolo, and E. E. B. Smith, Nature 172, 



1036 (1953). 



294 D. H. Marrian, Biochim. ei Biophys. Acta 12, 492 (1953). 



295 H. Schmitz, V. R. Potter, R. Hurlbert, and D. White, Cancer Research 14, 66, 

 (1954). 



296 H. Schmitz, Biochim. et. Biophys. Ada 14, 160 (1954). 



297 J. Baddiley and A. P. Mathias, Chemistry cfc Industry 1954, 277. 



