Analysis of Solid State 13C NMR Spectra of Biologically Active Compounds
Authors: Wawer I.; Witkowski S.
Source: Current Organic Chemistry, Volume 5, Number 10, October 2001 , pp. 987-999(14)
Publisher: Bentham Science Publishers
Abstract:
The characteristic features of 13C solid state NMR applications are discussed. The spectra are routinely measured with cross-polarisation (CP) pulse sequence and fast spinning under magic angle (MAS). Additional techniques (dipolar dephase, variation of cross-polarisation contact time) influence the signal intensities and enable selective observation of nonprotonated or protonated carbons. Solid state NMR is complementary to X-ray diffraction and provides structural information about solids when the attempts to grow suitable single crystals have failed. However the combination of both methods is more successful in characterisation of solid state conformations and dynamic processes.
Many medium sized molecules such as saccharides, amino acids, peptides, steroids, polyphenols (flavonoids), and tocopherol derivatives have been studied. Samples that are insoluble in commonly used solvents or easily decompose in solution should be investigated by solid state NMR. Since the method can be applied to crystalline as well as to amorphous powders it is especially interesting tool in the studies of macromolecules. Numerous results concerning peptides, proteins and polysaccharides are reported.
Keywords: cross polarisation CP; X ray diffraction; polyphenols flavonoids; tocopherol derivatives; polysaccharides; X-RAY DIFFRACTION XRD; Antioxidants; Flavonoids
Language: English
Document Type: Review article
DOI: 10.2174/1385272013374905

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