DETERMINATION OF A COMPLETE SET OF COUPLING-CONSTANTS IN C-13-LABELEDOLIGONUCLEOTIDES

Three experiments are introduced to determine a complete set of coupli ng constants in RNA oligomers. In the HCCH-E.COSY experiment, the vici nal proton-proton coupling constants can be measured with high accurac y. In the P-FIDS-CT-HSQC experiment, vicinal proton-phosphorus and car bon-phosphorus couplings are measured that depend on the phosphodieste r backbone torsion angles beta and epsilon. In the refocussed HMBC exp eriment, vicinal carbon-proton couplings are measured that depend on t he glycosidic torsion angle chi.