【摘要】 条斑紫菜 （Porphyrayezoensis）的热水提取物 ,经DE₂ 3和SephadexG₂ 0 0柱层析纯化 ,得到一种含微量硫酸基的琼胶精品 （PY1 ）。此多糖经Sepharose 6B柱层析鉴定为单一组分 ,分子量为 2 2 0kD。紫外光谱显示它不含蛋白质、多肽及核酸。红外光谱揭示它含 3,6_内醚_半乳糖的特征吸收以及微量的硫酸基。该多糖的水解产物经气相色谱分析 ,主要由半乳糖及其衍生物组成 ,有少量岩藻糖存在。通过高磺酸氧化和Smith除解以及1 3C_NMR谱的分析 ,该多糖主要由琼胶二糖结构单元和它的生物前体组成 ,以琼胶二糖为主更多还原

【Abstract】 The crude polysaccharide was extracted from Porphyra yezoensis with hot water and was then purified by DE₂3 and Sephadex G₂00 column chromatography. A purified polysaccharides （PY1） was obtained, which contains little sulfate. Its homogeneity was identified with Sepharose 6B column chromatography. The average molecular weight was estimated to be 220 kD. The ultraviolet spectrum showed there is no proteins and nucleic acids in PY1. And the infrared spectrum indicated that there are special absorption of 3,6_anhydro_galactose and very little sulfated absorbance peaks. Galactose and its derivatives were the main constituents by gas chromatography. Through periodate oxidation, Smith degradation and 13 C_NMR analysis, PY1 is mainly composed of agarobiose, and a little of its precusor exists as well.更多还原