Discovery of Unusual Highly Branched Galactomannan from Seeds of Desmanthus illinoensis
Autor: | Yukihiro Tamaki, Takeshi Teruya, Masakuni Tako |
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Rok vydání: | 2018 |
Předmět: |
chemistry.chemical_classification
biology Molecular mass 010405 organic chemistry Stereochemistry Chemical structure 010402 general chemistry biology.organism_classification Polysaccharide 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Galactomannan chemistry Desmanthus illinoensis Mass spectrum Side chain Specific rotation |
Zdroj: | Journal of Biomaterials and Nanobiotechnology. :101-116 |
ISSN: | 2158-7043 2158-7027 |
Popis: | A galactomannan was isolated from seeds of a leguminous plant, Desmanthus illinoensis, which is grown in Okinawa, Japan. D-Galactose (molar ratio, 1.0) and D-mannose (0.82) were identified via High-performance Anion Exchange Chromatography Coupled with a Pulse Amperometric Detector. The molecular mass and specific rotation were estimated to be 1000 kDa and +53.8°, respectively. The infrared spectrum indicated that the galactomannan was involved in both α- and β-linkages, and two types of α-linkages were detected at 814 and 830 cm-1. The 1H- and 13C-NMR spectra indicated that the majority of the β-D-mannan main chain was substituted with mono α-D-galactose or α-D-galacto-disaccharide-side chains. Methylation analysis was used to identify 2,3,4,6-tetra-O-methyl-D-galactose (molar ratio, 3.3), 2,3,4-tri-O-methyl- D-galactose (1.0) and 2,3-di-O-methyl-D-mannose (3.1). Specifically, unique 2,3,4-tri-O-methyl D-galactose residue was identified from mass spectrum. The results suggested that the galactomannan was 1,4-linked-β-D-mannan substituted with α-D-galactose or 1,6-linked-α-D-galacto-disaccharide side chains at C-6 on the main chain. The galactomannan isolated from D. illinoensis was an unusual highly branched polysaccharide, and its chemical structure was proposed. This work is the first to report on the galactomannan involving 1,6-linked α-D-galacto-disaccharide side chains in addition to α-D-galactose mono side chains. |
Databáze: | OpenAIRE |
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