The molecular weight of the polysaccharide and the chemical groups it contains has an important influence on its biological activity, relatively low molecular weight polysaccharides may have better antioxidant activity. Polysaccharides isolated from the fruiting bodies of Morchella sextelata (MSP) were treated by gamma-irradiation at 10, 100 and 1000 kGy doses, and the physicochemical properties and antioxidant activity of irradiated MSP were investigated. Microscopic observation under a scanning electron microscope (SEM) showed that breakage and pores appeared on the surface of the irradiated polysaccharide. As the irradiation dose increased, the average molecular weight of MSP decreased significantly, while the particle size and thermal stability of MSP first increased at 10 and 100 kGy doses and then decreased at 1000 kGy doses. The antioxidant activities, measured by free radical scavenging tests and protective effect on PC12 cells injured by H2O2, were all increased after irradiation, especially when the concentration of MSP was low (50 and 100 μg/mL). Therefore, irradiation treatment was an effective method to enhance the activity of polysaccharides.

中文翻译：

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γ射线辐照对羊肚菌子实体多糖的结构和抗氧化活性的影响

多糖的分子量及其所含的化学基团对其生物学活性具有重要影响，相对低分子量的多糖可能具有更好的抗氧化活性。以10 kGy，100 kGy和1000 kGy剂量分别对六味羊肚菌（MSP）子实体中的多糖进行了γ辐照处理，研究了辐照后MSP的理化性质和抗氧化活性。在扫描电子显微镜（SEM）下的显微镜观察表明，在照射的多糖的表面上出现破损和孔。随着辐照剂量的增加，MSP的平均分子量显着降低，而MSP的粒径和热稳定性首先在10和100 kGy剂量时增加，然后在1000 kGy剂量时降低。通过自由基清除测试测量的抗氧化活性和对H2O2损伤的PC12细胞的保护作用在辐照后均增加，尤其是在MSP浓度较低（50和100μg/ mL）时。因此，辐射处理是增强多糖活性的有效方法。