2-Deoxy-ribose

During digestive processes, nucleoprotein is split into nucleic acids and protein, the latter then being broken down into amino acids. The nucleic acids are attacked by ribonuclease and deoxyribonuclease enzymes to form nucleotides, which are further hydrolysed by nucleotidases to form nucleosides and phosphates. In the intestines these nucleosides are split by nucleosidases into ribose, deoxy-ribose, purine and pyrimidine bases, which later undergo oxidation and decomposition to ammonia, carbon dioxide and water, to be finally expelled as urea. Nucleotide hydrolysis products are conveniently identified and isolated by chromatographic methods (Chapter 14.2). 

The numbering scheme used for nucleosides maintains the independence of the two structural units The pyrimidine or purine is numbered m the usual way So is the car bohydrate except that a prime symbol ( ) follows each locant Thus adenosine is a nude oside of D nbose and 2 deoxyadenosine is a nucleoside of 2 deoxy d ribose... 

The same kind of 5 3 phosphodiester units that join the 2 deoxy d ribose units m Figure 28 I are also responsible for connecting nucleosides of d ribose... 

Section 28 2 Nucleosides are carbohydrate derivatives of pyrimidine and purine bases The most important nucleosides are derived from d ribose and 2 deoxy D ribose... 

Section 28 7 Nucleic acids are polynucleotides present m cells The carbohydrate component is D nbose m ribonucleic acid (RNA) and 2 deoxy d ribose m deoxyribonucleic acid (DNA)... 

Nucleic Acids. Phosphoms is an essential component of nucleic acids, polymers consisting of chains of nucleosides, a sugar plus a nitrogenous base, and joined by phosphate groups (43,44). In ribonucleic acid (RNA), the sugar is D-ribose in deoxyribonucleic acids (DNA), the sugar is 2-deoxy-D-ribose. 

Fragment A was synthesized from 2-deoxy-D-ribose by a modification of the approach previously described (Ref, 1) ... 

A commonplace variation on the general pattern seen in carbohydrate structure is the replacement of one or more of the hydroxyl substituents by some other atom or group. In deoxy sugars the hydroxyl group is replaced by hydrogen. Two examples of deoxy sugars are 2-deoxy-D-ribose and L-rhannose ... 

The hydroxyl at C-2 in D-ribose is absent in 2-deoxy-D-ribose. In Chapter 28 we shall see how derivatives of 2-deoxy-D-ribose, called deoxyribontideotides, are the fundamental building blocks of deoxyribonucleic acid (DNA), the material responsible for storing genetic information. L-Rhfflnnose is a compound isolated from a number of plants. Its carbon chain terminates in a methyl rather than a CH2OH group. 

The most important nucleosides are derived from D-ribose and 2-deoxy-D-ribose. 

Phosphodiester (Section 28.6) Compound of the type shown, especially when R and R are D-ribose or 2-deoxy-D-ribose. 

A more complicated reaction sequence has been used by Ukita and Nagasawa (59) in their synthesis of 2-deoxy D-ribose 5-phosphate (2-deoxy D-erythro-pentose 5-(dihydrogen phosphate)), (29). They phosphorylated a mixture of the anomeric methyl deoxyribofuranosides (24)... 

Generally speaking, the phosphorylated deoxysugars undergo the usual reactions of carbohydrates without complication. For instance, both 2-deoxy D-ribose 5-phosphate (52, 59) and 2-deoxy D-xylose 5-phosphate (2) can be reduced to the corresponding 2-deoxy d-erythro- (48) and 2-deoxy D-threo-pentitol 5-phosphates (49). 2-deoxy ribose 5-phosphate has also been oxidized (52) to the corresponding phosphorylated acid (50). 

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