流苏石斛多糖理化性质·免疫活性及提取工艺研究

Study on Physicochemical Properties,Immunomodulatory Activities and Extracting Technology of Polysaccharides from Dendrobium fimbriatum Hook

[目的]研究流苏石斛水溶性多糖(WDFP)、碱溶性多糖(BDFP)及酸溶性多糖(ADFP)的理化性质与免疫活性差异,并对WD-FP的提取工艺进行优化。[方法]分别以水、碱、酸提取流苏石斛获得WDFP、BDFP和ADFP,比较3者理化性质和免疫活性;并采用响应面法优化WDFP的提取工艺条件。[结果]WDFP、BDFP和ADFP的分子量分别为2.10×105、3.34×106和3.53×106Da,特性黏度分别为68.2、134.9和40.4 ml/g。WDFP主要由葡萄糖和甘露糖组成,BDFP主要由阿拉伯糖、木糖和葡萄糖组成,ADFP主要由木糖和葡萄糖组成。WDFP免疫调节活性最高,BDFP次之,ADFP最低。WDFP最佳提取条件为:提取温度82℃,提取时间51 min,料液比1∶33.3(W/V,g/ml,下同);在此条件下,提取得率为9.68%。[结论]研究结果为流苏石斛多糖的进一步研究提供基础,为其工业化生产提供参考。

[ Objective] The physicochemical properties and immunomodulatory activities of polysaccharides from Dendrobiumfimbriatum were investigated, and the extraction technology of WDFP was optimized. [ Method ] Different polysaccharidcs were obtained after stems of D. tim- briatum were extracted with water, base and acid solutions. The physicochemical properties and immunomodulatory activities of the three poly- saccharides were analyzed. The extraction technology of WDFP was optimized by response surface method. [ Result] The three polysaccharides were different in physicochemical properties and immunomodulatory activities. The molecular weights of WDFP, BDFP and ADFP were 2.10 × 105 , 3.34 ×106 and 3.53 × 106 Da, and their intrinsic viscosities were 68.2, 134.9, 40.4 ml/g, respectively. Monosaccharide compo- sition analysis showed that glucose and mannose existed in WDFP, arabinose, xylose and glucose in BDFP, and xylose and glucose in ADFP. Among three polysaccharides, WDFP had the highest immunomodulatory activity. The optimum extraction yield （9.69%） of WDFP was ob- tained under the conditions of extraction temperature of 82~C, extraction time of 51 min and ratio of water to materials of 33.3：1 （W/V）. [ Conclusion ] The study will provide a foundation for further exploitation and industrial production of polysaccharides from D. fimbriatum.