CHEMISTRY OF RIBOSE AND DEOXYRIBOSE 



41 



HO-CHj 'Os 



H H>H-OMe 



HO 

 = P0-CH2 ^0 



H-OH 



OH OH 

 XXXIX 



OH OH 

 XXXVIII 



A 



PhCHsO, 

 PhCHsO' 



:PO-CH 







H-OMe 



resin (monochloroacetate of Dowex 1). The overall yield of the pentose 

 phosphate from adenosine triphosphate was 63-70 %. As previously men- 

 tioned, ribose-5-phosphate can be obtained from ribose-1 -phosphate by the 

 mutase action of liver^"^ and yeast-"' extracts. D-Gluconic acid 6-phosphate 

 may be degraded enzymically to D-ribose-S-phosphate'**^- "*** and this 

 observation is relevant to any discussion on possible routes--^ for the 

 biogenesis of D-ribose. [Cf. Glock, Chapter 22.] Ribose-5-phosphate was 

 found to be vigorously metabolized by animal and yeast extracts,-'' • ^^^ 

 but arabinose-5-phosphate and xylose-5-phosphate were only slightly 

 attacked. 



(4) Other Pentose Phosphates. During the researches which led to the identification 



223 I. A. Bernstein, J. Am. Chem. Soc. 73, 5003 (1951). 



"^ F. Dickens, Biochem. J. 32, 1626, 1645 (1938). 



2" F. Dickens and Gertrude E. Glock, Nature 166, 33 (1950). 



