Nucleic acids nucleosides

Fig. 7.16 LAN (Locked nucleic acid) nucleosides as conformationally constrained nucleoside-derived A3 AR antagonists...

Journal of Carbohydrate Chemistry [/. Carbohydr. Chem.] (1982-). Successor to Journal of Carbohydrates, Nucleosides, Nucleotides [/. Carbohydr, Nucleosides, Nucleotides] (1974-1981), which was divided into Journal of Carbohydrate Chemistry md Nucleosides Nucleotides [Nucleosides Nucleotides] (1982-1999), later Nucleosides, Nucleotides Nucleic Acids [Nucleosides, Nucleotides Nucleic Acids]. Publisher Taylor Francis. 

Hollenstein, M., Gautschi, D. and Leumann, C. J. (2003) Fluorinated peptide nucleic acids. Nucleosides Nucleotides Nucleic Acids, 22, 1191-1194. 

Many anti-viral compounds are analogues of the natural nucleic acid nucleosides such as adenosine 225. This example 226, known as (5, 5 )-iso-ddA (dda stands for di-deoxy-adenosine), has a severely modified sugar 227 but the purine, adenine 228, is unaltered. The purine is attached to C-2 instead of C-1 making the molecule more stable and two of the OH groups have been removed. Coupling adenine to the modified sugar 227 needs a Mitsunobu process.42... 

In the past, the term nucleoside has had two connotations. It was first proposed by Levene and Jacobs for the carbohydrate derivatives of purines and pyrimidines obtained by the hydrolyas of nucleic acids, but since that time it has been more generally applied to aU naturally occurring glycosyl derivatives of purines and pyrimidines. The sugar moieties of nucleic acid nucleosides have so far proved to be either n-ribose or 2-deoxy-... 

This method for the synthesis of purine nucleosides, developed by Todd and coworkers, was valuable in that it unequivocally established that the point of attachment of the sugar moiety of the nucleic acid nucleosides is at N-9. In this synthesis, a sugar is condensed with a 4,6-diaminopyrim-idine (132) in alcohol solution in the presence of acid, and the resultant 4-amino-6-(glycosylamino)pyrimidine (133) is coupled with an aromatic diazonium salt. The (phenylazo)pyrimidine (134) is reduced to the amino compound (135), and cyclization to the purine nucleoside (137) is accomplished by way of the 5-thioformamide compound (136). 

Table 13-9. Hydrolysis of nucleic acids, nucleosides and their analogs.

M35. Muhlegger, K., Batz, H. G., Bohm, S., Eltz, H., Hditke, H. J., and Kessler, C. H., Synthesis and use of new digoxygenin-labeled nucleotides in non-radioactive labeling and detection of nucleic acids. Nucleosides Nucleotides 8, 1161-1163 (1988). 

See also Nucleic Acids, Nucleoside and Nucleotide Naming, Phosphodiester Bonds, RNA, Proteins... 

Zadrazil, Z. (1975) Low-molecular weight constituents of nucleic acids. Nucleosides, nucleotides and their analogues, pp. 831-57 in monograph cited in 214. 

Ribonucleic acids (RNA) - Naturally occurring polyribonucleotides. See also nucleic acids, nucleosides, nucleotides, ribonucleotides. [5]... 

How do nucleotides combine to give nucleic Acids Nucleosides are linked hy ester bonds to phosphoric acid to form the phosphodiester backbone. 

The ionizable phosphate group present in organic phosphorus species provides the basis for separation by anion exchange chromatography. This approach has been applied to the separation of phosphate, inositol phosphates, organic condensed phosphates, nucleic acids, nucleoside phosphonates, phospholipids and other organic phosphorus species. 

Interest continues in conformationally-locked bicyclic nucleosides and their oligomers. A report from Wengel s laboratory describes details of the synthesis of the a-L-LNA (locked nucleic acid) nucleoside 129, in which a key step is the treatment of ditosylate 128 with NaOH in aqueous ethanol to establish the bicycle, a reaction thought to involve a 2,2 -anhydronucleoside as an intermediate. Also reported is the similar conversion of 130 into the a-L-xy/o-LNA nucleoside 131." The effect on RNA binding of the incorporation of these two compounds, and the previously-prepared P-D-xyfo-isomer and LNA nucleoside itself, into oligonucleotides has been studied the behaviour of the other four stereoisomers of LNA, enantiomeric with those synthesized, was also studied... 

Fio, 18. Pyrimidine components of nucleic acids. Nucleosides of the pyrimidine bases are joined in d-glycosidic linkage from the first carbon of ribose to the nitrogen of position 1 of the ring (nitrogen 3 according to the old numbering system). The nucleotides are phosphoric acid esters of the nucleosides, usually substituted at carbon 5 of the ribose moiety. The proper chemical names for the nucleoside and nucleotide of uracil are l-jS-n-ribofuranosyluracil (uridine) and l-/ -5 -phospho-D-ribo. ... 

Purines occur as (i.) nucleosides, (ii.) mononucleotides, and (iii.) polynucleotides, or nucleic acids. Nucleosides are glycosides of a purine or pyrimidine base. Nucleotides are phosphoric esters of nucleosides, in which the phosphoric radicle is joined to the third or fifth carbon in the sugar residue. 

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