High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans
Three xylan fractions, obtained by stepwise precipitation with ethanol, were analysed by 75-MHz 13C-n.m.r. spectroscopy. Diad frequencies, determined from the C-2 resonances, show that the (1 → 3)-linkages are interspersed throughout the chain rather than grouped contiguously. This type of distribut...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_01418130_v14_n1_p29_Matulewicz |
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todo:paper_01418130_v14_n1_p29_Matulewicz2023-10-03T14:58:42Z High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans Matulewicz, M.C. Cerezo, A.S. Jarret, R.M. Syn, N. 13C-n.m.r. diad frequencies Xylans carbon xylan xylan article chemistry comparative study conformation isolation and purification methodology nuclear magnetic resonance spectroscopy optical rotation seaweed carbon nuclear magnetic resonance chemical bond chemical structure nonhuman Carbohydrate Conformation Carbon Isotopes Comparative Study Magnetic Resonance Spectroscopy Optical Rotation Seaweed Support, Non-U.S. Gov't Xylans Three xylan fractions, obtained by stepwise precipitation with ethanol, were analysed by 75-MHz 13C-n.m.r. spectroscopy. Diad frequencies, determined from the C-2 resonances, show that the (1 → 3)-linkages are interspersed throughout the chain rather than grouped contiguously. This type of distribution is in agreement with a random coil conformation and with the constancy of the optical rotation in solvents of different ionic strength and chaotropic power. These diad frequencies were compared with the theoretical values calculated for a random distribution from the ratio of (1 → 4)-:(1 → 3)-linkages in the 1H-n.m.r. spectra, and from the methylation analysis for one of the fractions. © 1992 Butterworth-Heinemann Limited. Fil:Matulewicz, M.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cerezo, A.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01418130_v14_n1_p29_Matulewicz |
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Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
13C-n.m.r. diad frequencies Xylans carbon xylan xylan article chemistry comparative study conformation isolation and purification methodology nuclear magnetic resonance spectroscopy optical rotation seaweed carbon nuclear magnetic resonance chemical bond chemical structure nonhuman Carbohydrate Conformation Carbon Isotopes Comparative Study Magnetic Resonance Spectroscopy Optical Rotation Seaweed Support, Non-U.S. Gov't Xylans |
| spellingShingle |
13C-n.m.r. diad frequencies Xylans carbon xylan xylan article chemistry comparative study conformation isolation and purification methodology nuclear magnetic resonance spectroscopy optical rotation seaweed carbon nuclear magnetic resonance chemical bond chemical structure nonhuman Carbohydrate Conformation Carbon Isotopes Comparative Study Magnetic Resonance Spectroscopy Optical Rotation Seaweed Support, Non-U.S. Gov't Xylans Matulewicz, M.C. Cerezo, A.S. Jarret, R.M. Syn, N. High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| topic_facet |
13C-n.m.r. diad frequencies Xylans carbon xylan xylan article chemistry comparative study conformation isolation and purification methodology nuclear magnetic resonance spectroscopy optical rotation seaweed carbon nuclear magnetic resonance chemical bond chemical structure nonhuman Carbohydrate Conformation Carbon Isotopes Comparative Study Magnetic Resonance Spectroscopy Optical Rotation Seaweed Support, Non-U.S. Gov't Xylans |
| description |
Three xylan fractions, obtained by stepwise precipitation with ethanol, were analysed by 75-MHz 13C-n.m.r. spectroscopy. Diad frequencies, determined from the C-2 resonances, show that the (1 → 3)-linkages are interspersed throughout the chain rather than grouped contiguously. This type of distribution is in agreement with a random coil conformation and with the constancy of the optical rotation in solvents of different ionic strength and chaotropic power. These diad frequencies were compared with the theoretical values calculated for a random distribution from the ratio of (1 → 4)-:(1 → 3)-linkages in the 1H-n.m.r. spectra, and from the methylation analysis for one of the fractions. © 1992 Butterworth-Heinemann Limited. |
| format |
JOUR |
| author |
Matulewicz, M.C. Cerezo, A.S. Jarret, R.M. Syn, N. |
| author_facet |
Matulewicz, M.C. Cerezo, A.S. Jarret, R.M. Syn, N. |
| author_sort |
Matulewicz, M.C. |
| title |
High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| title_short |
High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| title_full |
High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| title_fullStr |
High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| title_full_unstemmed |
High resolution 13C-n.m.r. spectroscopy of 'mixed linkage' xylans |
| title_sort |
high resolution 13c-n.m.r. spectroscopy of 'mixed linkage' xylans |
| url |
http://hdl.handle.net/20.500.12110/paper_01418130_v14_n1_p29_Matulewicz |
| work_keys_str_mv |
AT matulewiczmc highresolution13cnmrspectroscopyofmixedlinkagexylans AT cerezoas highresolution13cnmrspectroscopyofmixedlinkagexylans AT jarretrm highresolution13cnmrspectroscopyofmixedlinkagexylans AT synn highresolution13cnmrspectroscopyofmixedlinkagexylans |
| _version_ |
1807316132998152192 |