人参糖肽分离及性质

Isolation and Characterization of Glycopeptide from Panax ginseng

目的:从人参根中分离纯化人参糖肽组分P-Ⅱ并研究其理化性质。方法:首先采用50%乙醇提取,高浓度乙醇沉淀,活性炭脱色得到人参糖肽,经DEAE-Sepharose CL-6B柱分离,依次用0.2,0.5,1.0 mol·L-1的Na Cl水溶液洗脱,得到组分Ⅱ,然后利用Sephadex G-150柱分离,以0.2 mol·L-1的Na Cl水溶液洗脱得到P-Ⅱ;以葡萄糖、半乳糖醛酸和牛血清白蛋白为对照品测定中性糖、糖醛酸及肽的含量,以醋酸纤维薄膜层析、Sephadex G-100柱色谱、气相色谱分析仪、氨基酸分析仪对P-Ⅱ性质进行研究。结果:P-Ⅱ含中性多糖50.2%,糖醛酸38.5%,肽1.9%,P-Ⅱ为均一糖肽,糖部分的单糖组成为Rha,Ara,Glc和Gal,其摩尔比为0.45∶1.15∶1.00∶2.36,肽部分由Asp,Fhr,Ser等16种氨基酸组成。结论:分离得到的P-Ⅱ为均一糖肽,而不是糖和肽的混合物,为人参糖肽构效学研究奠定基础。

Objective： To purify a glycopeptide named P-Ⅱ from Panax ginseng and investigated its properties. Method： The glycopeptide was extracted by 50% ethanol, precipitated with high-concentration ethanol, after decolorized by active carbon obtained crude ginseng glycopeptide, then purified by DEAE-Sepharose CL-6B column, washed successively with 0.2, 0.5 and 1.0 mol ·L^-1NaCl aqueous solution. Then using Sephadex G-150 column eluted with an aqueous solution of 0.2 mol·L^-1 NaCl to give P-Ⅱ. The contents of neutral carbohydrate, uronic acid and peptide were determined using glucose, galacturonic acid and bovine serum albumin as the standards. The characterization of P-Ⅱ was analyzed by cellulose acetate membrane chromatography, Sephadex G-100 column chromatography, gas chromatography, and amino acid analysis. Result： P-Ⅱ was a homogneous glycopeptide. The contents of neutral carbohydrate, uronic acid, and peptide in P- Ⅱ were 50.2% , 38.5% , and 1.9% , respectively. The molar ratio of Rha, Ara, Glc and Gal was 0.45： 1. 15： 1.00： 2. 36. It was consisted 16 kinds of amino acids including Asp, Fhr, and Set. Conclusion： P-Ⅱ was a homogeneous glycopeptide, rather than a mixture of sugars and peptides, and laid the foundation for the study of structure-activity of ginseng glycopeptide.