多变量离散系统随机信号跟踪性能极限.PDF

156 2008, Vol. 29, No. 07 食品科学 ※工艺技术 1 2 3 2 周跃斌 ，王 伟 ，周向荣 ，李 适 (1.湖南农业大学产业处，湖南 长沙 410128 ；2.湖南农业大学天然产物研究中心，湖南 长沙 410128 ； 3.湖南省质量技术监督局标准化研究院，湖南长沙 410007) ：对毛竹叶采用超声波提取法获得的竹叶多糖粗提取物，采用Sevag 法脱蛋白质、乙醇分级沉淀、冷冻干 燥后得到粗多糖，进一步用DEAE-52 纤维素柱层析、Sephadex 葡聚糖凝胶柱层析等方法分离纯化。结果表明： Sevag 法脱蛋白3 次可脱除97.2% 的蛋白质；50% 浓度的乙醇沉淀多糖得率最高，为37.6% ；DEAE-52 纤维素柱层 析柱水洗脱的得率最高，为46.4% ；DEAE-52 纤维素柱层析柱2 次水洗脱获得的竹叶多糖经G-75 柱层析和G-100 柱 层析可得到白色粉末状的中性多糖。选择水和NaCl 溶液为洗脱剂的温和条件分离纯化多糖效果较好。 ：毛竹；竹叶多糖；柱层析；分离；纯化 Study on Isolation and Purification Technics of Polysaccharides Extracted from Leaves of Phyllostachys pubescens 1 2 3 2 ZHOU Yue-bin ，WANG Wei ，ZHOU Xiang-rong ，LI shi (1.Product Agent, Hunan Agricultural University, Changsha 410128, China； 2.Research Center for Natural Products, Hunan Agricultural University, Changsha 410128, China ； (3. Institute of Standardization, Hunan Bureau of Quality and Technology Supervision, Changsha 410007, China) Abstract：Polysaccharides were prepared from the leaves of Phyllostachys pubescens. The crude polysaccharides were extracted from the dried leaves by ultrasonic method and fractionated precipitation by 95% ethanol while the protein was removed with Savags method. After being further lyophilized, these polysaccharides were purified by DEAE-52 cellulose column chromatog- raphy and Sephadex glucan gel column chromatography, respectively. The results showed that Savags deprotein method can get rid of 97.2% protein with the yield of polysaccharide as high as 37.6% with 50% ethano