采用水提取分级醇沉制得宣木瓜多糖,利用苯酚-硫酸法测定多糖含量,采用高效尺寸排阻色谱-多角度激光光散射-示差折光联用技术(HPSEC-MALLS-RI)分析多糖分子量和分子量分布,用多糖体外刺激巨噬细胞,Griess法检测NO释放量.系列研究旨在考察宣木瓜多糖含量、分子量和分子量分布以及免疫活性,为宣木瓜多糖研究积累实验资料和科学依据;并为中药多糖研究提供较为简单、系统的方法与思路.结果表明,不同乙醇浓度(φ)沉淀宣木瓜多糖含量的高低顺序是:95%＞80%＞40%≥60%＞20%,95%乙醇可较完全地沉淀多糖;当乙醇浓度从20%上升到95%时,粗多糖纯度由35.1%上升至45.0%.宣木瓜多糖主要有3个色谱峰,不同浓度醇沉的多糖经HPSCE分离后出峰位置和数量没有明显差别,表明它们含有的多糖种类相似;重均分子量(Mw)分别为6.570×104 g·moL－1和1.393×104 g·moL－1以及小于1万未能获得准确值;前两种多糖的分子量分布指数(Mw/Mn)分别是1.336和1.639;本试验中宣木瓜多糖对巨噬细胞Raw264.7产生NO没有明显的促进作用。

Chaenomeles speciosa fruits were extracted using water.The extracts were precipitated with 20%～95%(φ) ethanol,respectively.The amount of total polysaccharide was measured with phenol-sulfuric acid method.A method using high-performance size-exclusion chromatography(HPSEC) equipped with multiangle laser-light-scattering photometry(MALLS) and differential refractometry(RI) was presented for determining the molecular weight and molecular weigh distribution.RAW264.7 macrophage were cultured and stimulated with the polysaccharides in vitro and the production of nitric oxide in the cells was determined by the Griess assay.The aim of the study is to determine the amount and the molecular weight of the polysaccharides from Chaenomeles speciosa fruits,and preliminary investigate the immunomodulatory activity,The study provided the basis datas for the further research of Chaenomeles speciosa fruits.,and provided a simple and system method for the research of natural polysaccharide.The ethanol fractional precipitation showed that the order of total polysaccharide content was 95%＞80%＞40%≥60%＞20%.The results indicated that most polysaccharide from Chaenomeles speciosa fruits might be precipitated when ethanol concentration was up to 95%(φ) and the crude polysaccharide purity had risen from 35.1% to 45.0% when the concentration of ethanol increased from 20% to 95%.HPSEC-MALLS-RI system showed that all the polysaccharide samples had the similar compositions.They appeared three chromatographic peaks and the retention time were not apparently different.The Mw were 6.570×104 g·mol-1and 1.393×104 g·mol-1 respectively,and one less than 10 000 which was failure to obtain accurate values.The molecular weight of the first two polysaccharide distribution index(Mw/Mn)were 1.336 and 1.639 respectively.The polysaccharide samples had not exhibited immunomodulatory activity assessed on the basis of nitric oxide production by RAW264.7 macrophage cells in the experiment.