香菇多糖锌螯合物的制备及结构表征和体外抗氧化活性研究

Preparation, structure characterization and in vitro antioxidant activity of lentinan-znic chelate

中文关键词:  香菇多糖  香菇多糖锌螯合物  单因素试验  响应面试验  结构表征  抗氧化活性

英文关键词:lentinan  lentinan-znic chelate  single factor test  response surface test  structure characterization  antioxidant activity

中文摘要:

      目的 制备香菇多糖锌螯合物(lentinan-znic chelate, LNT-Zn), 对其结构进行表征, 并考查其体外抗氧化活性。方法 以香菇为原料, 将提取纯化的香菇多糖与乙酸锌反应制备LNT-Zn, 通过紫外光谱、傅里叶变换红外光谱(Fourier transform infrared spectroscopy, FTIR)和场发射扫描电子显微镜(scanning electron microscopy, SEM)对其结构进行表征, 以原子分光光度法测定的LNT-Zn中锌离子质量分数为指标, 采用单因素试验和响应面试验优化LNT-Zn制备条件, 最后测定其对羟基自由基(·OH)、1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl radical, DPPH·)的清除率和总抗氧化活性等指标, 研究LNT-Zn的抗氧化活性。结果 LNT-Zn制备最佳条件为: 香菇多糖与乙酸锌的比例为1 g:8.68 mmoL、反应温度为49℃、反应时间为236 min、反应体系的pH为5.02; 在此条件下, 可制得锌离子含量为56.08 mg/g(相对标准偏差为0.69%)的LNT-Zn。紫外光谱和红外光谱结果表明, 香菇多糖中O-H、C-H、C-O-C和C=O等官能团与锌离子发生螯合。·OH和DPPH·清除试验和总抗氧化活性测定结果表明, LNT-Zn的抗氧化能力优于香菇多糖。结论 本研究建立的LNT-Zn的合成工艺切实可行, 可用于LNT-Zn的规模化合成, 可为香菇深加工及产品研发提供思路与理论参考。

英文摘要:

      Objective To prepare the lentinan-znic chelate (LNT-Zn), characterize its structure and investigate its in vitro antioxidant activity. Methods LNT-Zn was synthesized by the reaction between lentinan extracted and purified from Lentinus edodes and zinc acetate. The structure of LNT-Zn was characterized by ultraviolet spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Based on the zinc content in LNT-Zn determined by atomic spectrophotometry, single factor test and response surface test were used to determine the optimal preparation conditions for LNT-Zn. Finally, the antioxidant activity of LNT-Zn was evaluated by measuring the scavenging rates of hydroxyl radical (·OH), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and total antioxidant activity. Results The optimal conditions for preparing LNT-Zn were as follows: The ratio of lentinan to zinc acetate was 1 g:8.68 mmoL, reaction temperature was 49℃, reaction time 236 min, and the pH of the reaction system was 5.02, and the zinc content of LNT-Zn prepared under the optimized conditions was 56.08 mg/g (relative standard deviation was 0.69%). The results of ultraviolet spectroscopy and FTIR showed that the groups of O-H, C-H, C-O-C and C=O in LNT chelated with zinc ions. The results of ·OH, DPPH· scavenging tests and total antioxidant activity showed that LNT-Zn possessed stronger antioxidant capacity compared with lentinan. Conclusion The synthesis process of LNT-Zn established in this study is feasible, which can be used for large-scale synthesis of LNT-Zn, and provide ideas and theoretical references for further processing and product development of Lentinus edodes.