Strukturuntersuchungen an Mannanderivaten

✍ Scribed by N. Frank; H. Friebolin; G. Keilich; J. P. Merle; E. Siefert

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 546 KB
• Volume: 4
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270040513

✦ Synopsis

H-NMR investigations using a high resolution 220 MHz spectrometer were performed on methyl, acetyl and benzoyl derivatives of mannan from ivory nuts and Tubera salep, and on the corresponding D-mannopyranose derivatives. With the exception of the C(l) configuration the structure of these polysaccharides may be determined by comparing the coupling constants and chemical shifts of the substituted polysaccharides with those of the corresponding monosaccharide derivatives. The particularly broad signals in the spectra of low as well as high molecular weight acetyl and benzoyl mannans and furthermore, the differences between the chemical shifts of protons in 1,2,3,4,6-penta-O-acetYl-D-mannOp~anOSe and those of the benzoylated mannans, are discussed in terms of relatively small flexibility of the polymer chains or chain segments in solution. In addition studies to determine the type of glycosidic bonds in polysaccharides from a comparison of the d,,,,-values of various polyglycan derivatives are reported. Zusammenfassung-Die PR-Spektren einiger Methyl-, Acetyl-und Benzoylderivate von Mannan aus Steinnulj und Tubera salep sowie der D-Mannopyranose wurden analysiert. Durch einen Vergleich der Kopplungskonstanten und der Signallagen von entsprechend substituierten Polymeren und Monomeren wird, rnit Ausnahme der Konfiguration an C(1), die Struktur dieser Polysaccharide bestirnrnt. Es wird auf charakteristische Unterschiede der Resonanzlagen von H(l) in Polysacchariden mit a-bzw. &$ycosidischen Bindungen hingewiesen. Dieser Befund eroffnet die Moglichkeit ,