|Download illustrations in a single file (PDF, 2.3 Mb)|
Nowadays NMR spectroscopy is one of the most widely used methods in structural chemistry of natural compounds. Nevertheless, the experience from previous bio-organic schools and conferences in Russia showed that young scientists missed information on benefits of magnetic resonance methods in structural elucidation of natural compounds, and could not interpret NMR spectra in structural aspect. The lecture is aimed at compensation of this deficiency. It is a part of a lection series dedicated to the elucidation of regular polymeric structures composed of separate residues (monosaccharides, aminoacids, alditols etc.)
The lection includes a review of modern NMR spectroscopic methods applied to the determination of structure of a sample bacterial glycopolymer. The usage of most demanded NMR experiments (COSY, TOCSY, ROESY, HSQC, HMBC etc. at 1H, 13C, 31P nuclei) is discussed. The material is focused at spectra interpretation process and the visualization of spectra assignment. The opportunities of the NMR spectroscopy are demonstrated at the example of complete structural investigation of a polysaccharide antigen of the bacterium Edwardsiella tarda 1153. The structure of its tetrasaccharide unit containing non-carbohydrate moiety was elucidated in the Zelinsky Institute carbohydrate chemistry lab in 2009. The lection links various NMR spectra to the structural peculiarities of the O-antigen: monomeric composition, anomeric and absolute configurations of residues, linkage positions, sequence of residues, monosaccharide modifications and stoichiometry.
The lecture is an educational overview and contains information on existing instrumental methods, active usage of which has become possible for the recent decades.
Last update: 2011 Sep 15 Home