Salvia miltiorrhiza polysaccharides were generally extracted using distilled water as solvent and showed various bioactivities in vivo, however, the preparation, structure, and immunomodulatory effects of polysaccharides with 60 % ethyl alcohol extraction were rarely reported. In the present study, S. miltiorrhiza polysaccharides was prepared using 60 % ethanol and the extraction process was optimized, then the structural characteristics and immunomodulation activity were investigated. Results showed that optimal extraction conditions for crude polysaccharides were determined as follows: liquid/solid ratio of 22 mL/g, extraction temperature of 60 °C, ultrasonic power of 205 W, ultrasonic time of 125 min, and the yields reached to 5.99 ± 0.09 %. Structural determination results demonstrated the purified polysaccharides showed a average molecular weight of 6.50 × 10³ Da with Galactose/Glucose/Fructose ratio of 1.00:0.45:0.28. Animal experiments indicated that the polysaccharides could effectively enhance immune cells activities, and improve lymphocytes subsets proportions and immune-related cytokines expression levels dose-dependently in cyclophosphamide-treated mice. These results would provide a theoretical basis for industrial production and practical application of the novel polysaccharides as an immunoregulation adjuvant.

丹参多糖一般以蒸馏水为溶剂提取，在体内表现出多种生物活性，但60%乙醇提取多糖的制备、结构和免疫调节作用鲜见报道。在本研究中，丹参以60%乙醇为原料制备多糖，优化提取工艺，考察其结构特征和免疫调节活性。结果表明，粗多糖的最佳提取条件确定为：液固比22 mL/g，提取温度60 ℃，超声功率205 W，超声时间125 min，得率达到5.99 ± 0.09%。结构测定结果表明，纯化后的多糖平均分子量为 6.50 × 10 ³Da 的半乳糖/葡萄糖/果糖比为 1.00:0.45:0.28。动物实验表明，多糖可有效增强免疫细胞活性，并呈剂量依赖性地提高环磷酰胺处理小鼠的淋巴细胞亚群比例和免疫相关细胞因子的表达水平。这些结果将为新型多糖作为免疫调节佐剂的工业化生产和实际应用提供理论依据。