大粒车前子多糖组分PLP-1的结构表征

研究了由大粒车前子多糖分离纯化所得组分PLP-1的一级精细结构特征. 通过单糖组成分析、部分酸水解及甲基化分析，并结合NMR，GC和GC-MS等技术测定了PLP-1的一级结构. 结果表明，PLP-1由Ara（33.98%），Xyl（58.23%），Rha（2.36%），Glc（2.23%），Gal（2.36%）和Man（0.83%）组成，糖醛酸以GlcA形式存在. PLP-1中主要糖残基有α-T-linked Araf（9.58%），β-T-linked Xylp（8.71%），α-1，3-linked Araf（18.22%），β-1，3-linked Xylp（8.05%），β-1，4-linked Xylp（5.85%），β-1，2，4-linked Xylp（16.98%）和β-1，3，4-linked Xylp（27.52%），GlcA以α-T-linked GlcAp形式存在；此外还有1，2-linked Rhap，T-linked Glcp，1，6-linked Glcp，T-linked Galp，1，3-linked Galp和1，3，6-linked Galp等少量其它残基. 根据所得结果推断出PLP-1可能的一级结构.

Structural Characterization of Purified Polysaccharide Fraction(PLP-1) from the Seeds of Plantago asiatica L.

Polysaccharide's biological activities are related to their structure. Previous studies showed that the polysaccharide from seeds of Plantago asiatica L. had good bioactivities, and two fractions from the crude polysaccharide were characterized. This work aimed at investigating primary structure of another fraction, PLP-1. The methods, including monosaccharide compositions analysis, partial acid hydrolysis, nuclear magnetic resonance(NMR), gas chromatography(GC) and gas chromatography-mass spectroscopy(GC-MS), were applied for structural characterization. The results showed that PLP-1 was composed of Ara(33.98%), Xyl(58.23%), Rha(2.36%), Glc(2.23%), Gal(2.36%) and Man(0.83%). Its main uronic acid was GlcA. The majority residues were α-T-linked Araf(9.58%), β-T-linked Xylp(8.71%), α-1,3-linked Araf(18.22%), β-1,3-linked Xylp(8.05%), β-1,4-linked Xylp(5.85%), β-1,2,4-linked Xylp(16.98%) and β-1,3,4-linked Xylp(27.52%). GlcA was existed as α-T-linked GlcAp. There were other residues, including 1,2-linked Rhap, T-linked Glcp, 1,6-linked Glcp, T-linked Galp, 1,3-linked Galp and 1,3,6-linked Galp, etc. Finally, primary structure of PLP-1 was proposed.