Linear β-mannose-containing polysaccharide, β-xylan, and amylose from the cultured photobiont Trebouxia sp. of the ascolichen Ramalina celastri

摘要: Abstract The cultured photobiont Trebouxia sp. of Ramalina celastri was successively extracted at 100°C with hot water, 2% aqueous KOH, and 10% KOH to give polysaccharide-containing fractions A (2.9%), B (3.9%), C (0.9% yield) respectively. intact biont contained 3.8% amylose, which present in each fraction, identified by a blue color formed iodine solution. In fraction A, following retrogradation from solution, it characterized 13C-NMR spectroscopy. Fraction treated α-amylase water-soluble consisting mainly β-mannose-containing polysaccharides (1.5% yield), whose main component had dn/dc 0.162 Mr 17 kDa. subjected freeze–thawing the precipitate resistant, linear, low molecular mass (1→4)-linked β-xylan. β- D -mannopyranan preparation 3-O- (28%), 4-O- (11%), 6-O-substituted Manp units (35%), 3-O-substituted Rhap (11%). controlled Smith degradation provided β-mannan nonreducing end- (8%), (85%) units, showing (1→3)- (1→6)-linked structures original polysaccharide. These could be as block-type structures.