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13 C nuclear magnetic resonance spectroscopy of selected adenine nucleosides: Structural correlation and conformation about the glycosidic bond
Author(s) -
Akhrem A. A.,
Mikhailopulo I. A.,
Abramov A. F.
Publication year - 1979
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270120416
Subject(s) - glycosidic bond , chemistry , substituent , stereochemistry , vicinal , alkane stereochemistry , nuclear magnetic resonance spectroscopy , molecule , carbohydrate , crystallography , enzyme , organic chemistry
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.