Linear beta-mannose-containing polysaccharide, beta-xylan, and amylose from the cultured photobiont Trebouxia sp. of the ascolichen Ramalina celastri
| ISSN: | 0378-1097 |
|---|---|
| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::977059acbf88d092a5701f56cbc8be2d https://pubmed.ncbi.nlm.nih.gov/12644232 |
| Rights: | OPEN |
| Přírůstkové číslo: | edsair.doi.dedup.....977059acbf88d092a5701f56cbc8be2d |
| Autor: | Júlio César David Ferreira, Philip A.J. Gorin, Lucimara M.C. Cordeiro, Marcello Iacomini, Cesar A. Tischer, Rodrigo A. Reis |
| Rok vydání: | 2003 |
| Předmět: |
Trebouxia
Hot Temperature Retrogradation (starch) Lichens Mannose Polysaccharide Cell Fractionation Microbiology chemistry.chemical_compound Ascomycota Amylose Chlorophyta Polysaccharides Genetics Carbohydrate Conformation Amino Acids Molecular Biology Nuclear Magnetic Resonance Biomolecular chemistry.chemical_classification Aqueous solution Chromatography biology Molecular mass Plant Extracts Water biology.organism_classification Xylan chemistry Xylans |
| Zdroj: | FEMS microbiology letters. 220(1) |
| ISSN: | 0378-1097 |
| Popis: | The cultured photobiont Trebouxia sp. of Ramalina celastri was successively extracted at 100 degrees C with hot water, 2% aqueous KOH, and 10% aqueous KOH to give polysaccharide-containing fractions A (2.9%), B (3.9%), and C (0.9% yield) respectively. The intact biont contained 3.8% amylose, which was present in each fraction, and was identified by a blue color formed with iodine solution. In fraction A, and following retrogradation from aqueous solution, it was characterized by (13)C-NMR spectroscopy. Fraction B was treated with alpha-amylase to give a water-soluble fraction consisting mainly of beta-mannose-containing polysaccharides (1.5% yield), whose main component had dn/dc 0.162 and M(r) 17 kDa. Fraction C was subjected to freeze-thawing and the precipitate was treated with alpha-amylase to give a resistant, linear, low molecular mass (1-->4)-linked beta-xylan. The beta-D-mannopyranan preparation contained mainly of 3-O- (28%), 4-O- (11%), and 6-O-substituted Manp units (35%), with 3-O-substituted Rhap units (11%). A controlled Smith degradation provided a beta-mannan with nonreducing end- (8%), 3-O- (85%) and 6-O-substituted units, showing (1-->3)- and (1-->6)-linked structures in the original polysaccharide. These could be present as block-type structures. |
| Databáze: | OpenAIRE |
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