平贝母多糖铁配合物的合成、结构特征及抗氧化活性

Preparation, Structural Characteristics and Antioxidant Activity of Polysaccharide-Iron Complex from Fritillaria ussuriensis

目的:以平贝母多糖为原料,制备平贝母多糖铁配合物,对其理化性质、结构特征以及抗氧化活性进行研究。方法:采用水提醇沉法提取平贝母多糖,对其结构进行化学修饰,得到平贝母多糖铁配合物。利用紫外-可见光谱、红外光谱、X-射线粉末衍射、扫描电镜、能谱、热重-差热分析等测定平贝母多糖和多糖铁配合物的理化性质和结构特征,在此基础上,通过清除1,1-二苯基-2-三硝基苯肼(1,1-dipheny1-2-picryl-hydrazyl,DPPH)自由基、超氧阴离子自由基和羟自由基的能力评估多糖的抗氧化效果。结果:平贝母多糖提取率为4.66%,表征手段证实了平贝母多糖铁配合物的成功合成,并且多糖与Fe^3+络合后,未改变多糖结构的基本骨架,此外,多糖铁配合物结构稳定性更强,平贝母多糖铁配合物对DPPH自由基、超氧阴离子自由基、羟自由基有清除作用,并且均强于平贝母多糖,分别达到最大清除率为68.96%、57.28%、46.88%。结论:平贝母多糖经Fe3+修饰后,结构稳定性增加,可显著提高体外抗氧化活性。

Objective:To prepare polysaccharide-iron complex from the bulbs of Fritillaria ussuriensis,and to evaluate its physicochemical properties,structural characteristics and antioxidant activity.Methods:The structure of the polysaccharide extracted by water extraction and then alcohol precipitation was chemically modified to obtain its iron complex.Ultraviolet-visible spectroscopy,infrared spectroscopy,X-ray powder diffraction,scanning electron microscopy(SEM),and thermogravimetric-differential thermal analysis were used to determine the physicochemical properties,and structural characteristics of the polysaccharide and its iron complex.Moreover,their antioxidant activities were evaluated by 1,1-dipheny1-2-picryl-hydrazyl(DPPH),superoxide anion and hydroxyl radical scavenging assays.Results:The extraction yield of F.ussuriensis polysaccharide was 4.66%.The characterization confirmed the successful synthesis of polysaccharideiron complex.The basic structure framework of the polysaccharide was not changed after complexation with Fe^3+.In addition,the structural stability of polysaccharide-iron complex was stronger.The complex had stronger radical scavenging effects than the polysaccharide and the maximum scavenging rates were 68.96%,57.28%and 46.88%for DPPH,superoxide anion and hydroxyl radicals,respectively.Conclusion:The structural stability of F.ussuriensis polysaccharide increased after being modified with Fe^3+,leading to a significant increase in the antioxidant activity in vitro.