CHEMISTRY OF RIBOSE AND DEOXYRIBOSE 13 



nucleotide linkages. A discussion of these linkages forms the subject of 

 Chapter 12. 



In addition to its occurrence as a component of ribonucleic acid and of 

 nucleotides like adenosine di- and triphosphate, D-ribose has been found in 

 combination with uric acid in the blood^" and united with 2-hydroxy-(i- 

 aminopurine (isoguanine) in the croton l)ean {Croton tiqlium L.).'"'^'- 

 2-Hydroxy-6-aminopurine-D-riboside (sometimes called crotonoside) can 

 be isolated from the croton seed by extraction with methanol, and Spies 

 and Drake''^ succeeded in obtaining from it crystalline D-ribose. The pentose 

 also occurs in certain vitamins and coenzymes. Acidic degradation of 

 vitamin B12 results in the formation of l-(Q;-D-ribofuranosyl)-5,6-dimethyl- 

 benzimidazole,^'*"^* and it has been shown that the ribofuranose moiety of 

 the vitamin is phosphorylated at either C-2 or C-3.^^ Coenzyme I (diphos- 

 phopyridine nucleotide) and coenzyme II (triphosphopyridine nucleotide) 

 isolated by Euler et alP'^^ and by Warburg et al}'^ from yeast and red 

 blood cells, respectively, coenzyme A''^ and the coenzyme of "galactowal- 

 denase" — uridine diphosphate glucose^^ — all have substituted ribose com- 

 ponents as part of their molecules. (See also Chapter 4 and Schlenk^-^ and 

 Romberg and Pricer^^ for further details.) Leloii- has suggested that 

 ribose-1 , 5-diphosphate is probably a coenzyme for the enzyme responsible 

 for the conversion of ribose-1 -phosphate to ribose-5-phosphate. Over a 

 quarter of a century ago Winter"*^ obtained a substance from certain animal 



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 (1922) 



31 E. Cherbuliez and K. Bernhard, Helv. Chirn. Acta 15, 464 (1932). 



32 E. Cherbuliez and K. Bernhard, Helv. Chim. Acta 15, 978 (1932). 



33 J. R. Spies and N. L. Drake, J. Avi. Chem. Soc. 57, 774 (1935). 



3^N. G. Brink, F. W. Holly, C. H. Shunk, Elizabeth W. Peel, J. J. Cahill, and K. 

 Folkers, J. Am. Chem. Soc. 72, 1866 (1950). 



35 N. G. Brink and K. Folkers, J. Am. Chem. Soc. 71, 2951 (1949); 72, 4442 (1950). 



36 E. R. Holiday and V. Petrow, J. Pharm. and Pharmacol. 1, 734 (1949). 



3' G. R. Beaven, E. R. Holiday, E. A. Johnson, B. Ellis, P. Mamalis, V. Petrow, 

 and B. Sturgeon, /. Pharm. and Pharmacol. 1, 957 (1949). 



38 J. G. Buchanan, A. W. Johnson, J. A. Mills, and A. R. Todd, Chemistry d- In- 

 dustry 1950, 426; J. Chem. Soc. 1950, 2845. 



33 H. V. Euler, H. Albers, and F. Schlenk, Z. physiol. Chem. 237, 1 (1935). 



■"' H. V. Euler, and F. Schlenk, Z. physiol. Chem. 246, 64 (1937). 



^1 H. V Euler, P. Karrer, and E. Usteri, Helv. Chim. Acta 25, 323 (1942). 



« O. Warburg, W. Christian, and A. Griese, Biochem. Z. 282, 157 (1935). 



"3 J. Baddiley, E. M. Thain, G. D. Novelli, and F. Lipmann, Nature 171, 76 (1953). 



^* R. Caputto, L. F. Leloir, C. E. Cardini, and A. C. Paladini, J. Biol. Chem. 184, 

 333 (1950). 



" F. Schlenk, J. Biol. Chem. 146, 619 (1942). 



^« A. Romberg and W. E. Pricer, Jr., J. Biol. Chem. 186, 557 (1950). 



"L. B. Winter, Biochem. J. 21, 467 (1927). 



