探究灰树花多糖F2中发挥降血糖功效的核心成分。采用Sephacryl S-200 层析柱对灰树花多糖F2进行纯化得到多糖F21和F22，对其进行结构表征和降血糖效果评价。结果表明，F21是由岩藻糖、半乳糖、葡萄糖和甘露糖组成，分子量约为17.9 ku；F22是由甘露糖和葡萄糖组成，分子量约为3.16 ku。动物实验发现，F21(i.g.)降低了T2DM小鼠空腹血糖16.36%（P<0.05），减少了甘油三酯26.53%（P<0.05）；F22(i.g.)降低了低密度脂蛋白31.48%（P<0.01）。F21(i.p.)降低了空腹血糖约22.32%（P<0.05）；血浆谷丙转氨酶、谷草转氨酶和碱性磷酸酶分别降低了32.96%（P<0.001）、36.12%（P<0.05）、42.35%（P<0.001）；肝脏丙二醛含量减少了42.95%（P＜0.001），超氧化物歧化酶和过氧化氢酶活性分别增加了36.08%（P＜0.05）、24.34%（P＜0.01）。F22(i.p.)降低了肝脏中碱性磷酸酶水平32.38%(P<0.01) ，增加了超氧化物歧化酶活性37.32% (P<0.05)，减少了丙二醛含量68.16%（P<0.001）。结果表明，灰树花多糖F2的活性成分为F21，其可以改善T2DM小鼠症状，该研究为灰树花多糖在食药领域上的开发应用提供了理论依据，具有广阔的应用前景。

The core components of Grifola frondosa polysaccharide F2 that play a role in lowering blood sugar were explored. The Sephacryl S-200 column was applied to separate and purify to obtain two kinds of polysaccharide F21 and F22 from Grifola frondosa pol-ysaccharide F2, and their structural characterization and hypoglycemic effect were evaluated. The animal experiments showed that the polysaccharide F21 was composed of fucose, galactose, glucose and mannose, and its molecular weight was about 17.9 ku. F22 is composed of mannose and glucose and has a molecular weight of about 3.16 ku. Compared with diabetes model group, F21(i.g.) decreased fasting blood glucose by 16.36% (P<0.05) and triglyceride by 26.53% (P<0.05) in T2DM mice. F22(i.g.) decreased low density lipoprotein level in T2DM mice by 31.48% (P<0.01). F21(i.p.) decreased the fasting blood glucose of T2DM mice by 22.32% (P<0.05). Plasma alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were decreased by 32.96% (P<0.001), 36.12% (P<0.05) and 42.35% (P<0.001), respectively, compared with diabetes group. Liver malondialde-hyde content was decreased by 42.95% (P < 0.001), superoxide dismutase and catalase activities were increased by 36.08% (P < 0.05) and 24.34% (P < 0.01), respectively. F22(i.p.) decreased the level of alkaline phosphatase by 32.38%(P<0.01), increased the activity of superoxide dismutase by 37.32% (P<0.05), and decreased the content of malondialdehyde by 68.16% (P<0.001). The results showed that the active component of Grifola frondosa polysaccharide F2 is F21, which can improve the symptoms of T2DM mice. This study provides a theoretical basis for the development and application of Grifola frondosa polysaccharide in food and medicine, and has a broad application prospect.

广东省重点领域研发计划项目（2022B0202020004）;国家食品营养与安全重点研发计划专项（2023YFF1104100）; 国家自然科学基金（82373770）; 广东省自然科学基金（2023A1515030151）