Comparative study by circular dichroism of the conformation of deazapurine nucleosides and that of common purine nucleosides.
AUTOR(ES)
Miles, D W
RESUMO
Purine nucleoside analogs modified by replacement of the nitrogen atom at the 3 position by a CH group give a characteristic circular dichroism curve that is not substantially modified by chemical substitution at the 8 position. Since it is rather well established that 8-substituted purine nucleosides are predominantly in the syn conformation in aqueous solution, it follows that the 3-deazapurine nucleosides, whether substituted at position 8 or not, also favor the syn conformation. These data are in sharp contrast to the circular dichroism data obtained on 8-halogenated and 8-alkylated derivatives of adenosine and guanosine, which give circular dichroism profiles substantially different from those obtained on the parent compounds. Certain purine-nucleoside-utilizing enzymes fail to interact effectively with either the unsubstituted 3-deaza analogs or the 8-substituted derivatives of adenosine and guanosine. The hypothesis recently given that the inactivity of the 8-substituted derivatives springs from their syn-conformational preference is tentatively accepted to explain the inactivity of the 3-deaza analogs.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=430576Documentos Relacionados
- Conformation of nucleosides: circular dichroism study on the syn-anti conformational equilibrium of 2-substituted benzimidazole nucleosides.
- Glycosyl conformational and inductive effects on the acid catalysed hydrolysis of purine nucleosides.
- Conformation of Cyclolinopeptide A Observed by Circular Dichroism
- Acetylation and cleavage of purine nucleosides. Synthesis of 6-azauridine, 5-fluorouridine, and 5-methyluridine.
- Influence of divalent cations on the conformation of phosphorothioate oligodeoxynucleotides: a circular dichroism study