生漆多糖的分离与结构研究

生漆用丙酮提取不溶解物，除去其水不溶部分、依次进行７３２阳离子交换树脂和ＳｅｐｈａｄｅｘＧ－１００柱层析、得到白色粉末漆多糖．分子量１２．５×１０￣４．其组成为Ｄ－半乳糖、Ｄ－葡萄糖醛酸、Ｌ－阿拉伯糖和Ｌ－鼠李糖．摩尔比为７．７：１．８：０．４：０．１．经羧基还原、甲基化反应、高碘酸盐氧化、Ｓｍｉｔｈ降解和ＧＣ－ＭＳ、ＩＲ、￣１Ｈ－ＮＭＲ、￣１３Ｃ－ＮＭＲ分析、结果表明，漆多糖为多分支结构、分子主链由β（１→３）Ｄ－半乳糖基构成．部分半乳糖基Ｃ＿６位有支链，另有部分半乳糖基以（１→６）键连接，其中β（１→３）与β（１→６）甙键糖基组成比为１．８３：１．分子的支链由葡萄糖醛酸基、阿拉伯糖基、鼠李糖基组成，并且葡萄糖醛酸基构成分子的末端基．

STUDIES ON SAPARATION AND STRUCTURE OF LACQUER POLYSACCHARIDE

The lacquer polysaccharide (LPS)was isolation from Sap of lacquer tree (Rhus Vernicifera), and purified by 732 cation -exchange resin and Sephadex G-100 column Chromatography. Its monosaccharide components were identified by paper and gas chromatography as following: D-galactose, D-glucuronic acid, L-Aiabinose and L- Rhamnose (7.7:1.8: 0.4:0. 1 by mol). The molecular wieght (Mw) was obtained to be 1.25 × 10￣5 by HPGPC. The LPS was subjected to reduction of carboxyl groups, mathylation, periodate okidation and Smith degradation, and then was analyst by GC- MS, IR, ￣1H-NMR, ￣13C- NMR. The results showed that LPS consists of a β (1→ 3 ) D-galactose main chain with a number of side chains, which consist of glucuronic add Arabinose and Rhamnose. The side chains place on some of the galactose residues at C_6 position with content ratio of β (1→ 3) to β (1→ 6) (1.83 :1).