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Measurement of one‐bond proton‐carbon coupling constants of saccharides
Author(s) -
Uhrínova Stanislava,
Uhrían Dušan,
Liptaj Tibor,
Bella Juraj,
Hirsch Ján
Publication year - 1991
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260290909
Subject(s) - chemistry , anomer , proton , coupling constant , pulse sequence , spectral line , analytical chemistry (journal) , molecule , chemical shift , nuclear magnetic resonance spectroscopy , proton nmr , mannose , spectroscopy , carbon fibers , monosaccharide , stereochemistry , crystallography , nuclear magnetic resonance , organic chemistry , physics , materials science , particle physics , quantum mechanics , astronomy , composite number , composite material
Abstract Several NMR experiments, one proton and several carbon detected, were used for the determination of 1 J (C,H) values in saccharides. Couplings of anomeric carbons were measured from the 13 C satellites in 1 H NMR spectra. The simultaneous application of several purging schemes resulted in a very good suppression of the proton signals from 12 C molecules. 1 J (C,H) values of all saccharides were determined by 2D J ‐resolved spectroscopy using an INEPT‐type pulse sequence with a BIRD pulse for the suppression of n J (C,H) and folding in F 1 . Rules for the calculation of the correct values of 1 J (C,H) from the observed reduced splittings are proposed. 1 J (C,H) values were also obtained from a set of J ‐modulated one‐dimensional 13 C spectra. A procedure for the determination of 1 J (C,H) values from only two one‐dimensional experiments is proposed. Mannose derivatives (mono‐ and poly‐saccharides) were used to test and compare the individual methods. Differences in 1 J (C,H) values for C‐2 and C‐3 were used for the chemical shift assignment of these carbons.