山豆根木葡聚糖的研究

Studies on Xyloglucan from Sophora subprostrata

研究了山豆根中一种木葡聚糖的结构．用１ｍｏｌ／ＬＮａＯＨ提取，ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５离子交换柱层析，Ｆｅｈｌｉｎｇ试剂分级得到山豆根木葡聚糖组分ＳＳｂ－１ＦＡ，用完全酸水解，甲基化分析，部分酸水解，三氧化铬氧化和１Ｈ，１３ＣＮＭＲ等方法对其结构进行研究．结果表明：ＳＳｂ－１ＦＡ的分子量为２．６×１０４，比旋光度［α］２０Ｄ＝＋１０．９°（ｃ０．２２，Ｈ２Ｏ），由Ｌ－Ｆｕｃ，Ｄ－Ｘｙｌ，Ｄ－Ｇａｌ和Ｄ－Ｇｌｃ组成，摩尔比为：２．９２９．９７．５５９．８．ＳＳｂ－１ＦＡ由１→４连接的β－Ｄ－Ｇｌｃ残基构成主链，分枝有α－Ｄ－Ｘｙｌ（１→，β－Ｄ－Ｇａｌ（１→２）α－Ｄ－Ｘｙｌ（１→等类型，部分非还原末端由Ｌ－Ｆｕｃ（１→构成．

To study the characteristics and structure of xyloglucan from Sphyora subprostrata ,The roots of Sophora subprostrata was extracted sequentially with boiling water and 1 mol/L NaOH.From the alkaline extract,a polysaccharide,SSb 1 FA was separated using DEAE Sephadex A 25 ion exchange chromatography and Fehling reagents complexing.Its structure was studied by composition analysis,methylation analysis,CrO 3 oxidation,partial hydrolysis and NMR method.SSb 1 FA was found to be composed of L Fuc, D Xyl, D Gal and D Glc,in the ratios of 2 9∶29 9∶7 5∶59 8,with the molecular weight of 2 6×10 4 and 20 D=+10 9°(c 0 22,H 2O),The Results showed that SSb 1 FA contained a backbone composed of 1→4 linked β D Glc,with α D Xyl(1→,β D Gal(1→2)α D Xyl(1→ or α L Fuc(1→2)β D Gal(1→2)α D Xyl(1→ as branches,substituting at O 6 of glucosyl residues.