Homonuclear long-range correlation spectra from HMBC experiments by covariance processing.
We present a new application of covariance nuclear magnetic resonance processing based on 1H--13C-HMBC experiments which provides an effective way for establishing indirect 1H--1H and 13C--13C nuclear spin connectivity at natural isotope abundance. The method, which identifies correlated spin networks in terms of covariance between one-dimensional traces from a single decoupled HMBC experiment, derives 13C--13C as well as 1H--1H spin connectivity maps from the two-dimensional frequency domain heteronuclear long-range correlation data matrix. The potential and limitations of this novel covariance NMR application are demonstrated on two compounds: eugenyl-beta-D-glucopyranoside and an emodin-derivative.
Schoefberger
Wolfgang
W
Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
Smrecki
Vilko
V
Vikić-Topić
Drazen
D
Müller
Norbert
N