Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10605276 | Carbohydrate Polymers | 2005 | 8 Pages |
Abstract
Two different exopolysaccharides (EPSs) were obtained by submerged mycelial culture of an edible mushroom, Collybia maculata TG-1, and their chemical structures were studied by gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, methylation analysis, and NMR spectroscopy. A compositional analysis result by GC indicated that both EPSs (designated as Fr-I and Fr-II) were galactomannans consisting of mainly mannose and galactose. FT-IR spectroscopy was used for obtaining vibrational spectra of the EPSs. In the anomeric region (950-700 cmâ1), both EPSs exhibited the characteristic absorption at 810 cmâ1 corresponding to the existence of mannose. The obvious absorption peaks at 910 and 880 cmâ1 in both EPSs revealed the co-existence of α and β configurations. In a 13C NMR analysis, two anomeric peaks appeared at 102.0 and 99.6 ppm, which were assigned to the mannose (C-1) and galactose (C-1) residues, respectively. In a GC-MS analysis, the methlylation data confirmed the presence of a (1â3)-linked β-d-mannopyranosyl backbone mainly substituted O-6 by galactopyranosyl residues. The size exclusion chromatography/multi-angle laser light scattering (SEC/MALLS) system showed that the weight-average molecular mass of the Fr-I and Fr-II were 7.95Ã104 and 2.09Ã104 g/mol, respectively. Moreover, the SEC/MALLS revealed that the molecular conformation of the Fr-I was a random coil, with Fr-II being a rigid rod in aqueous solution.
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Authors
Jong Min Lim, Ji Hoon Joo, Hyun Oh Kim, Hyun Mi Kim, Sang Woo Kim, Hye Jin Hwang, Jong Won Yun,