Structural analysis of a pectic polysaccharide from boat-fruited sterculia seeds.
Structural analysis of a pectic polysaccharide from boat-fruited sterculia seeds.
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DOI：
10.1016/j.ijbiomac.2013.01.005
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发表时间：
2013-05
影响因子：
8.2
通讯作者：
Yan Wu;Lian-zhong Ai;Jinhong Wu;S. Cui
中科院分区：
文献类型：
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作者：
Yan Wu;Lian-zhong Ai;Jinhong Wu;S. Cui
采用部分酸水解、甲基化分析和1D/2D核磁共振（NMR）技术对从胖大海（Semen Sterculiae Lychnophorae）中分离得到的一种水溶性果胶多糖（Sterculia APS）的化学结构进行了鉴定。部分酸水解结果表明，胖大海APS的主链含有半乳糖醛酸和鼠李糖，支链含有阿拉伯糖、半乳糖和木糖。结合甲基化分析结果和核磁共振谱，推测APS的可能结构为：高半乳糖醛酸聚糖（HG）由1，4-α-d-GalpA线性连接而成，称为“光滑”区域;鼠李糖半乳糖醛酸聚糖-I（RG-I）由鼠李糖单元的O-4位部分取代而成，称为“多毛”区域。GalpA残基在C-2和/或C-3上部分甲酯化和0-乙酰化。侧链主要由阿拉伯聚糖和阿拉伯半乳聚糖组成，并通过T-、1，3-、1，5-l-Araf和T-、1，4-、1，6-、1，3，6-、1，3，4-d-Galp连接到骨架的O-4位。
The chemical structure of a water-soluble pectic polysaccharide (sterculia APS) isolated from boat-fruited sterculia seeds (Semen Sterculiae Lychnophorae) was elucidated using partial acid hydrolysis, methylation analysis and 1D/2D nuclear magnetic resonance (NMR) spectroscopy. The results of partial acid hydrolysis revealed that sterculia APS contained galacturonic acids and rhamnose units in the backbone, and arabinose, galactose and xylose residues in the branched chains. Combined the methylation analysis results with NMR spectroscopy, a possible structure of APS was proposed as follow: the backbone consisted of the homogalacturonan (HG) named “smooth” regions by linear linkage of 1,4-α-d-GalpA, and the rhamnogalacturonan-I (RG-I) called “hairy” ones by the linkage of →4)-α-d-GalpA-(1→2)-α-l-Rhap-(1→partially substituted at O-4 of rhamnose units. The GalpA residues were partially methyl esterified and O-acetylated on C-2 and/or C-3. The side chains were mainly composed of araban and arabinogalactan by the linkages of T-, 1,3-, 1,5-l-Araf and T-, 1,4-, 1,6-, 1,3,6-, 1,3,4-d-Galp, attached to O-4 of the backbone rhamnose units.