13C nuclear magnetic resonance spectroscopy of selected adenine nucleosides: Structural correlation and conformation about the glycosidic bond

✍ Scribed by A. A. Akhrem; I. A. Mikhailopulo; A. F. Abramov

• Book ID: 102951695
• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 690 KB
• Volume: 12
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270120416

✦ Synopsis

Abstract

Structural correlations have been carried out from ^13^C chemical shifts (δ) and by analysis of ^1^J(CH) coupling constants, and the conformation about the glycosidic bond has been studied by means of the ^3^J(CH) vicinal coupling constants between C‐8 and H‐1′ of some adenine nucleosides such as adenosine (Ado), N(7)‐β‐D‐ribofuranosyladenine (N(7)‐Ado), N(9)‐ and N(7)‐β‐D‐xylofuranosyladenine (N(9)‐xylAde and N(7)‐xylAde), N(9)‐(3‐chloro‐3‐deoxy‐β‐D‐xylofuranosyl)adenine (3′‐Cl‐xylAde) and N(9)‐(2‐chloro‐2‐deoxy‐β‐D‐arabinofuranosyl)adenine (2′‐Cl‐araAde). The analysis of the influence on δ^13^C of the nature and configuration of the substituent in the carbohydrate fragment of the molecule has revealed two types of effects, namely, 1,2‐cis and 1,2‐trans. This approach, as well as the ^3^J(CH) values and the analysis of the C‐3′‐endo⇌C‐2′‐endo equilibrium of the carbohydrate fragment of nucleosides, and circular dichroism (CD) data, provides important information on the conformation about the glycosidic bond. The magnitudes of ^3^J(C‐4, H) are indicative of the position of attachment of the carbohydrate fragment to the heterocyclic base.