不同分子量段蛹虫草多糖的超滤分离及其对巨噬细胞释放NO的影响

Separation by Ultrafiltration of Different Molecular Weight Fractions of Cordyceps militaris and Their Effect on Nitric Oxide Release from Macrophages

用超滤法将蛹虫草(Cordyceps militaris)子实体水提物分为<10kDa(PW1)、10～100kDa(PW2)、100～300kDa(PW3)、300～750kDa(PW4)和>750kDa(PW5)5个部分,并测定了这5部分的总糖含量、单糖组成及其对巨噬细胞释放NO产量的影响。结果表明,蛹虫草粗提物总得率(PW1～PW5之和)为38.35%,其中PW1得率最高(36.482%),其次是PW2(1.822%),PW3～PW5的得率都很低;各部分的总糖含量都较高(45.70%～60.48%)。单糖组成分析表明,各部分的多糖分别由3～6种单糖组成,其中甘露糖、葡萄糖、半乳糖为主要单糖。PW2～PW5均具有刺激巨噬细胞释放NO的活性,且随着浓度的增加活性增强。

Hot water（100 ℃） extracts of Cordyceps militaris fruit bodies were separated by membrane ultrafiltration into five different molecular weight fractions as follows： PW1〈10 kDa,PW2 10～100 kDa,PW3 100～ 300 kDa,PW4 300-750 kDa,PW5〉750 kDa.The total yield of extract was 38.35%（based on the dry weight of starting material）,and consisted of 36.428% PW1,1.822% PW2,and much smaller amounts of the three remaining fractions.Polysaccharide concentrations in the five fractions,as measured using the phenol sulfuric acid method,ranged between 45.70% and 60.48%.HPLC analysis revealed that the polysaccharide material in the different fractions was composed of between three and six monosaccharides,with relatively high levels of mannose,glucose and galactose recorded in fractions PW3-PW5.Nitric oxide production by RAW264.7 macrophages was stimulated by fractions PW2-PW5 in a concentration-dependent manner.