猫爪草多糖RTG-Ⅲ的分离纯化及其生物活性

Purification and properties of a polysacchande RTG-Ⅲ from Ranunculus ternali

目的 研究中药猫爪草水提取液中分离纯化得到一种多糖蛋白复合物——RTG-Ⅲ的生化特性、免疫和抑瘤作用。方法 采用DEAE-Cellulose-52和Superdex 200柱色谱得到均一的多糖组分,电泳和凝胶色谱等方法检测纯度,薄层色谱和气相色谱分析单糖组成,红外光谱确定糖苷键类型,噻唑蓝试验测定免疫活性。结果 RTG-Ⅲ为均一组分,单糖组成为鼠李糖、阿拉伯糖、葡萄糖、半乳糖、甘露糖,其摩尔比为1.00:1.17:51.71:2.16:0.46,总糖含量为80.1％,蛋白含量为12.6％,由谷氨酰胺、谷氨酸等16种氨基酸组成,糖肽键为非O-型。结论 RTG-Ⅲ是以β-D-葡萄吡喃糖为主的一种新的多糖-蛋白复合物,相对分子质量为2.3×104,能够增强免疫细胞对肿瘤细胞HL-60的抑制作用。

OBJECTIVE To purify a polysaccharide named RTG-Ⅲ from the water extraction of Ranunculus ternali Thunb. and to investigate its properties and bioactivity. METHODS RTG-Ⅲ was purified by DEAE-Cellulose-52 and Superdex 200 column chromatography. The homogeneity of RTG-Ⅲ was checked by electrophoresis and gel chromatography. Sugar composition was determined by TLC and GC. MTT assay was used to analyze immunological activity. RESULTS RTG-Ⅲ was homogeneous and consisted of Rha, Ara, Glc, Gal and Man in the molar ratio of 1.00:1.17:51.71:2.16:0.46. Its saccharide and protein content were 80.1 % and 12.6% respectively. Its protein portion consisted of Glu, Gln and other 16 kinds of amino acids. The characteristic absorption in IR spectrum was indicative of the β-D-glucosidic linkage. The saccharide and protein of RTG-Ⅲ was linked by non- O-glycosidic bond. CONCLUSION RTG- m is a new polysaccharide-protein complex and its molecular weight is about 2.3 × 104 . It can significantly inhibit the growth of HL-60 cell by enhancing immunological activity.