ABSTRACT The preparation conditions of Glehniae Radix polysaccharide-iron complex (GLP80-Fe) were optimized and the physicochemical properties were characterized by Ultraviolet-visible spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscope (TEM), Thermogravimetric analyzer, and Differential scanning calorimetry (TGA-DSC), respectively. The stability and reducibility of GLP80 and GLP80-Fe were analyzed, and the monosaccharide composition was determined by gas chromatograph (GC). In vitro antioxidant activity of GLP80 and GLP80-Fe were evaluated by determining the radical (DPPH and hydroxyl radical) scavenging abilities. The results showed that the highest iron content of GLP80-Fe (15.61%±0.04) was obtained at the optimum conditions: reaction temperature was 38.0°C, reaction time was 3.0 h, FeCl3 addition was 2.9 mL and pH was 9. GLP80-Fe was a complex with β-FeOOH as the core and polysaccharides on its surface, and it was stable at pH 3 ~ 14. GC showed that the major monosaccharides were mannose (Man) and galactose (Gal) with a ratio of 1:5.15. In vitro free-radical scavenging activity of GLP80-Fe was significantly better than GLP80. The IC50 of GLP80-Fe against DPPH and hydroxyl radical were 3.785 mg/mL and 1.460 mg/mL, respectively.

中文翻译：

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葛根多糖铁复合物的结构特征及抗氧化活性

摘要 优化了地参多糖-铁络合物（GLP80-Fe）的制备条件，并通过紫外-可见光谱（UV-Vis）、傅里叶变换红外光谱（FT-IR）、X射线衍射（ XRD)、透射电子显微镜 (TEM)、热重分析仪和差示扫描量热法 (TGA-DSC)。分析了GLP80和GLP80-Fe的稳定性和还原性，并通过气相色谱仪（GC）测定了单糖组成。GLP80 和 GLP80-Fe 的体外抗氧化活性通过测定自由基（DPPH 和羟基自由基）清除能力来评估。结果表明，在最佳条件下，GLP80-Fe铁含量最高（15.61%±0.04）：反应温度为38.0℃，反应时间为 3.0 h，FeCl3 添加量为 2.9 mL，pH 为 9。GLP80-Fe 是以 β-FeOOH 为核心，表面多糖的复合物，在 pH 3~14 下稳定。GC 表明主要单糖为甘露糖(Man)和半乳糖(Gal)，比例为1:5.15。GLP80-Fe 的体外自由基清除活性明显优于 GLP80。GLP80-Fe 对 DPPH 和羟基自由基的 IC50 分别为 3.785 mg/mL 和 1.460 mg/mL。