CHEMISTRY OF NUCLEOSIDES AND NUCLEOTIDES 



177 



■0- 



NH2 ^^ 



MeCMe 



/\ 

 O OCH.Ph 



I 



l-CH-CH-CH-CH-CHrOP-OAg 

 II 

 O 



-o- 



MeCMe 



LCH-CH-CH-CH-CHs-I 

 OH 



(1) boiling toluene 



(2) Huso, 



NH, 



k 



t.y 



OH 



N^^N 



N 



o=k 



■OH 

 -OH 



■OH 

 •OH 



CHrO- 



OH 



I 

 ■P O-CH. 



II 

 



Adenosine-5' uridine-5' phosphate 



tertiary base.^^' The resulting 2',3'-isopropylidene adenosine-5'-benzyl 

 phosphate is converted into its silver salt which in turn reacts with 2',3'- 

 isopropylidene-5'-iodo-5'-deoxyuridine. The isopropylidene and benzyl 

 groups were removed from the resulting neutral ester by gentle acid hy- 

 drolysis. 



4. Properties of Nucleotides 



The nucleotides resemble the nucleosides in many of their physical prop- 

 erties. They are colorless and for the most part crystalline solids with high 

 melting points, frequently decomposing before melting. They are strong 

 acids, soluble in water and insoluble in organic solvents. Their physical 

 properties (Table II) are often rather unreliable for characterization pur- 

 poses, and this fact was largely responsible for the failure of the early in- 

 vestigators to recognize the multiple nature of some of their materials. The 

 most satisfactory methods for the identication of nucleotides are those em- 

 ploying ion-exchange and paper-chromatographic analysis, often combined 

 with ultraviolet spectroscopy. [Cf. Chapters 6, 7, and 14.] 



5. Nucleotide Coenzymes 



Nucleotides of adenine and uridine occur as structural units not only of 

 the nucleic acids but also of certain coenzymes. The widespread occurrence 



211 J. Baddiley, V. M. Clark, J. J. Michalski, and A. R. Todd, J. Chem. Soc, 1949, 815. 



