Structural analysis and molecular characterization of exopolysaccharides produced by submerged mycelial culture of Collybia maculata TG-1
Structural analysis and molecular characterization of exopolysaccharides produced by submerged mycelial culture of Collybia maculata TG-1
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DOI：
10.1016/j.carbpol.2005.04.004
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发表时间：
2005-08-29
影响因子：
11.2
通讯作者：
Yun, JW
中科院分区：
文献类型：
--
作者：
Lim, JM;Joo, JH;Yun, JW
采用液体深层培养法从斑点Collybia maculata TG-1的菌丝体中分离得到2种胞外多糖（EPS），并利用气相色谱（GC）、傅立叶变换红外光谱（FT-IR）、甲基化分析和核磁共振波谱（NMR）等方法对其化学结构进行了研究。气相色谱分析结果表明，两种EPS（分别命名为Fr-I和Fr-II）均为半乳甘露聚糖，主要由甘露糖和半乳糖组成。FT-IR光谱用于获得EPS的振动光谱。在异头区（950-700 cm ~（-1）），两种EPS均在810 cm ~（-1）处有特征吸收，对应于甘露糖的存在。两种EPS在910和880 cm（-1）处的明显吸收峰揭示了α和β构型的共存。在C-13 NMR分析中，在102.0和99.6 ppm处出现两个异头峰，其分别归属于甘露糖（C-1）和半乳糖（C-1）残基。在GC-MS分析中，甲基化数据证实存在（1->3）-连接的β-D-吡喃甘露糖基骨架，其主要被吡喃半乳糖基残基取代O-6。体积排阻色谱/多角度激光光散射（SEC/MALLS）分析表明，Fr-I和Fr-II的重均分子量分别为7.95 × 10 ~（4）和2.09 × 10 ~（4）g/mol。此外，SEC/MALLS显示，Fr-I的分子构象是一个无规卷曲，与Fr-II是一个刚性杆在水溶液中。(C)2005爱思唯尔有限公司保留所有权利。
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 cm(-1)), both EPSs exhibited the characteristic absorption at 810 cm(-1) corresponding to the existence of mannose. The obvious absorption peaks at 910 and 880 cm(-1) in both EPSs revealed the co-existence of alpha and beta configurations. In a C-13 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 (1-->3)-linked beta-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 7.95 X 10(4) and 2.09 X 10(4) 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. (C) 2005 Elsevier Ltd. All rights reserved.