杜仲叶酸性多糖EOP-1的分离纯化、结构解析

摘要

The crude polysaccharide was extracted by hot water from leaves of eucommia ulmoides oliver.The deproteinization and decolorization of the polysaccharide was by Savage method and H 2 O 2 method,respectively. EOP-1 was purified by sepharose CL-6B column chromatography from the crude polysaccharide.HPSEC-RI analysis showed that the melocular weigh of EOP-1 was about 6.0×10 5 D.The structural features of polysaccha-ride EOP-1 were studied by partial acid hydrolysis and methylation methods,combined with GC-MS instru-ment,and the results indicated that EOP-1 was a kind of pectic polysaccharide which contained the main part of homogalacturonan fragments and the residues of sugar constituents were mainly D-GalpA,D-Galp,L-Araf and L-Rhap and the backbone was composed of 1,4-linked-D-GalpA and 1,4-D-Galp,1,6-D-Galp,1,5-L-Araf,1,2-L-Rhap were the mainly consititution of the branch,with a relative molar ratio of 45.1 1∶35.9∶0.9∶10.5∶6.9.%采用热水提取、用 Savage法除蛋白,过氧化氢法脱色得到杜仲叶粗多糖(crude polysaccharide from leaves of eucommia ulmoides oliver).经Sepha-rose CL-6B 分离纯化得到杜仲多糖的一个组分EOP-1,通过 HPSEC分析其纯度及测定分子量,表明该多糖约为6．0×105 D.部分酸水解和甲基化分析,结合GC-MS测试手段,对杜仲多糖 EOP-1的糖链结构进行了研究.结果显示,EOP-1的糖残基主要由 D-GalpA、D-Glcp、D-Galp、L-Araf 和 L-Rhap 组成,主链由1,4-D-GalpA连接,为半乳糖醛酸聚糖,侧链主要由1,4-D-Galp、1,6-D-Galp、1,5-L-Araf、1,2-L-Rhap 构成,其相对摩尔百分比为45．11∶35．9∶0．9∶10．5∶6．9.