The structures and cytotoxic activities of water-soluble polysaccharides were investigated to search for biologically active polysaccharides from the fruit bodies of quinine conks (Fomitopsis officinalis). The decoctions of this medical fungus are actively used in folk medicine in many countries and traditional Chinese medicine. From the fungal extract we prepared, only branched β-glucan had cytotoxic activity among all the water-soluble polysaccharides. This glucan is characterized by a regular structure. Its backbone is formed by 1,3-linked β-D-Glcp residues, of which every third residue is substituted at O-6 by a single β-D-Glcp residue. It has a triple helix conformation according to the data obtained from a colorimetric assay with Congo red dye and is characterized by a high-weight average molar mass (Mw > 800 kDa). β-Glucan possessed cytotoxic activity against HeLa cells (IC50 = 318 ± 47 μg/mL) and induced the formation of apoptotic bodies around most cancer cells at a concentration of 200 μg/mL. It should be noted that extraction with boiling water, which is usually used to obtain extracts and decoctions, is unable to isolate active β-glucan. Active β-glucan can be obtained in an individual state by cold alkali extraction after dehydration of the fruit bodies and removal of the components extractable by boiling water.

中文翻译：

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药用真菌奎宁康克子实体水溶性多糖的结构研究和细胞毒活性比较

研究了水溶性多糖的结构和细胞毒活性，以从奎宁锥 (Fomitopsis officinalis) 的子实体中寻找具有生物活性的多糖。这种药用真菌的汤剂在许多国家的民间医学和传统中药中被积极使用。从我们制备的真菌提取物中，只有支链 β-葡聚糖在所有水溶性多糖中具有细胞毒活性。这种葡聚糖的特点是结构规则。其骨架由 1,3-连接的 β-D-Glcp 残基形成，其中每三个残基在 O-6 处被单个 β-D-Glcp 残基取代。根据从刚果红染料比色法获得的数据，它具有三螺旋构象，其特征在于高重均摩尔质量 (Mw > 800 kDa)。β-葡聚糖对 HeLa 细胞具有细胞毒活性 (IC50 = 318 ± 47 μg/mL)，并在浓度为 200 μg/mL 时诱导大多数癌细胞周围凋亡小体的形成。需要注意的是，通常用于获得提取物和煎剂的沸水提取无法分离出活性β-葡聚糖。活性β-葡聚糖可以在子实体脱水后通过冷碱提取并通过沸水去除可提取的成分以个体状态获得。