不同分子质量块菌多糖的体外抗氧化活性

Antioxidant Activity in vitro of Polysaccharides with Different Molecular Weights from Truffles

目的:研究不同分子质量块菌多糖的体外抗氧化作用。方法:利用超滤法分离块菌粗多糖(TIP)得到3种不同分子质量的多糖组分,TIP-Ⅰ(<50ku)、TIP-Ⅱ(50～100ku)、TIP-Ⅲ(>100ku)。以总还原能力、DPPH自由基清除率、.OH清除率、O-2.清除率和螯合铁离子能力为指标,考察不同质量浓度条件下各块菌多糖组分的体外抗氧化活性。结果:总还原能力由强到弱依次为TIP-Ⅲ>TIP-Ⅱ>TIP-Ⅰ>TIP;螯合铁离子能力为TIP-Ⅰ>TIP-Ⅱ>TIP-Ⅲ>TIP,其IC50值分别为2.70、3.06、3.91、19.55mg/mL;TIP-Ⅲ清除自由基的能力最强,其清除DPPH自由基、.OH、O-2.的IC50值分别为2.83、1.67、4.71mg/mL。结论:不同分子质量的块菌多糖均具有抗氧化作用,且抗氧化能力与其分子质量密切相关。

Objective： To study the antioxidant activity in vitro of polysaccharides with different molecular weights from truffles.Methods： Three polysaccharide fractions were obtained from crude polysaccharides（TIP） from truffles by ultrafiltration centrifugation,TIP-Ⅲ（greater than 100 ku）,TIP-Ⅱ（between 100 ku and 50 ku） and TIP-Ⅰ（less than 50 ku）.The antioxidant activity of the polysaccharide fractions was evaluated by reducing power,DPPH,hydroxyl,superoxide anion radical scavenging,and Fe2＋-chelating assays.Results： TIP and these polysaccharide fractions were ranked in decreasing order： TIP-Ⅲ,TIP-Ⅱ,TIP-Ⅰand TIP by reducing power,and TIP-Ⅰ,TIP-Ⅱ,TIP-Ⅲ and TIP by Fe2＋-chelating ability with IC50 values of 2.70,3.06,3.91 mg/mL and 19.55 mg/mL,respectively.TIP-Ⅲ had the strongest scavenging activity against DPPH,hydroxyl and superoxide anion radicals with IC50values of 2.83,1.67 mg/mL and 4.71 mg/mL,respectively.Conclusion： All the polysaccharides with different molecular weights from truffles have antioxidant potential,which might be closely associated with their relative molecular weight.