三级片视频播放,精品三级片在线观看,A级性爱视频,欧美+日韩+国产+无码+小说,亲子伦XX XX熟女,秋霞最新午夜伦伦A片黑狐,韩国理伦片漂亮的保拇,一边吃奶一边做边爱完整版,欧美放荡性护士videos

文獻名： Sulfated modification, characterization and property of a water-insoluble polysaccharide from Ganoderma atrum

 

作者： Hui Zhanga, b , Jun-Qiao Wanga, Shao-Ping Niea, Yuan-Xing Wanga , Steve W. Cui a, b , Ming-Yong Xiea

a State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China

b Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ont., Canada N1G 5C9

 

摘要：Sulfated modification was carried out to modify a water-insoluble polysaccharide from Ganoderma atrum (AGAP). The effects of sulfation on structure, physicochemical and functional properties of AGAP were investigated. Three sulfated derivatives were prepared, designated as S-1, S-2 and S-3 with degree of substitution (DS) of 0.35, 0.74 and 1.14, respectively. AGAP was elucidated as an α-(1→3)-glucan with few branches terminated by single mannose or xylose residues. The molecular weight (Mw) and radius of gyration (Rg) were estimated to be 1665 kDa and 65.49 nm, respectively. After sulfated modification, non-selective sulfation occurred preferably at O-6, partially at O-2 and O-4 positions of the glucosyl residues. The water-solubility of the derivatives was significantly improved in a DS-dependent manner. Mw of the derivatives showed a sharp decrease, and the chain conformation was estimated to be expanded stiff in phosphate buffer. In vitro tests showed that sulfated modification improved its antioxidant activities and anti-proliferative ability against S-180 tumor cells. This study suggested that sulfated modification was an effective approach to improve the water-solubility and functional properties of insoluble polysaccharides.

 

關鍵詞：Ganoderma atrum; Water-insoluble polysaccharide; Sulfated modification; Structure; Physicochemical property; Antioxidant activity