2 -Deoxy adenosine 2 -Deoxyadenosine 5 -triphosphate

P 2 -deoxyadenosine 5 -diphosphate + trans-farnesyl triphosphate S 2 -deoxy-adenosine 5 phosphate -I- trans-farnesyl diphosphate <1> (<1>... 

When two acid molecules condense by elimination of a molecule of water, the product is called an acid anhydride, as can be seen in Figure 12.60. Acid anhydrides are always very reactive, or high-energy, compounds. When deoxy-adenosine monophosphate forms an anhydride with phosphoric acid, we have deoxyadenosine diphosphate (dADP). Of course, if we add an additional phosphate group, we have deoxyadenosine triphosphate (dATP). 

If the sugar is deoxyribose rather than ribose, the nucleoside has "deoxy" as a prefix (e.g., deoxyadenosine). Nuoleotides are given the name of the nucleoside plus mono, di, or triphosphate (e.g., adenosine triphosphate or deoxyadenosine triphosphate). 

Figure 1-3 shows a number of nucleoside antibiotics which contain adenine and an unusual sugar at the 9-position. Cordycepin (3 -deoxy-adenosine) is a cytostatic agent and is converted to the 5 -mono-, di-, and triphosphate derivatives in mouse tumor cells. Cordyceps militaris, the organism which produces cordycepin, also produces a related analogue with antitumor activity, 3 -amino-3 -deoxyadenosine this compound is also metabolized by way of phosphate derivatives. The angustmycins, psicofuranine and decoyinine, are, respectively, the 9-j3-D-psicofuranosyl... 

Severe combined immunodeficiency disease The enzyme adenosine deaminase degrades deoxyadenosine which is produced during DNA degradation (Chapter 10). Deficiency of the enzyme results in accumulation of deoxyadenosine which is a substrate for adenosine kinase and leads to production of deoxyadenosine and deoxyquanosine triphosphates, which reach high concentrations. This disturbs the balance of deoxy nucleotides which results in failure of DNA replication. This enzyme is normally present in lymphocytes so that a deficiency prevents proliferation of the lymphocytes, which is essential in combatting an infection. Consequently, patients are very susceptible to infections. This is one disease that is effectively treated by gene therapy. 

Syntheses of the adenosine and guanosine 5 -phosphoroazidates (622) and (613), which were required as affinity labels, of P -di([ C]adenosine-5 )penta-phosphate, an inhibitor of adenylate kinase (E.C. 2.7.4.3), and, by improved procedures, of 3 -deoxyadenosine (cordycepin) 5 -triphosphate have been reported. 2 -Deoxy-2 -deuterio-adenosine (276) (see p. 100) and its 2 -epimer have been converted into the corresponding 3, 5 -phosphates, whose conformers were examined by H n.m.r. spectroscopy." ... 

The base plus the sugar group (without the phosphate group) is called a nucleoside. Nucleosides are named from the bases. For example, the nucleoside composed of adenine with jS-D-ribose is called adenosine. The nucleoside composed of adenine with 2-deoxy-j8-D-ribose is called deoxyadenosine. A nucleotide is named by adding monophosphate (or diphosphate or triphosphate) after the nucleoside name. A number with a prime indicates the position of the phosphate group on the ribose ring. Thus, adenosine-5 -monophosphate is a nucleotide composed of adenine, jS-D-ribose, and a phosphate group at the 5 position of jS-D-ribose. 

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