研究不同生长期马齿苋茎叶提取物的抗氧化活性。分别用70%乙醇和水浸提不同生长期马齿苋茎、叶部分,用分光光度法测定其醇提物和水提物中多糖和总黄酮的含量,进行体外抗氧化活性实验。盛花期马齿苋茎中的多糖和黄酮含量最高,但水提物高...研究不同生长期马齿苋茎叶提取物的抗氧化活性。分别用70%乙醇和水浸提不同生长期马齿苋茎、叶部分,用分光光度法测定其醇提物和水提物中多糖和总黄酮的含量,进行体外抗氧化活性实验。盛花期马齿苋茎中的多糖和黄酮含量最高,但水提物高于醇提物。不论是水提物还是醇提物,不同生长期马齿苋茎中的多糖含量高于叶,而叶中的黄酮含量高于茎。在实验浓度范围内,两种溶剂提取物均有良好的抗氧化活性,随着提取物浓度的增加对羟基自由基（·OH）的清除能力增强,而对Ce（Ⅳ）的还原能力并不都是随浓度的增加而增强。在添加量为0.10~0.60 m L时,水提物对·OH的清除能力强于Vc,各个生长期马齿苋茎、叶水提物的抗氧化力强于醇提物,同一生长期茎对·OH的清除率都大于叶。添加量为0.50 m L时,水提物对Ce（Ⅳ）还原率最大的是花蕾期茎和盛花期叶达到79.64%。添加量为0.80 m L时,水提物对·OH的清除率最大的是花蕾期茎高达82.81%,醇提物对·OH的清除率最大的也是花蕾期茎为75.86%。展开更多
A novel polyglycidylmethacrylate(PGMA) microspheres with high adsorption capacity of Cr(VI) was prepared by cerium(IV) initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microsp...A novel polyglycidylmethacrylate(PGMA) microspheres with high adsorption capacity of Cr(VI) was prepared by cerium(IV) initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups.The micron-sized PGMA microspheres were prepared by a dispersion polym-erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups.The polymer microspheres were characterized by scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR).The results indicated that the polymer microspheres had an average diameter of 5 μm with uniform size distribution.The free amino group content was determined to be 5.13 mmol?g?1 for g-PGMA-NH2 mi-crospheres by potentiometric and conductometric titration methods.The Cr(VI) adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity(500 mg?g?1).The polymer microspheres with grafted tentacle polymer chains have poten-tial application in large-scale removal of Cr(VI) in aqueous solution.展开更多
文摘研究不同生长期马齿苋茎叶提取物的抗氧化活性。分别用70%乙醇和水浸提不同生长期马齿苋茎、叶部分,用分光光度法测定其醇提物和水提物中多糖和总黄酮的含量,进行体外抗氧化活性实验。盛花期马齿苋茎中的多糖和黄酮含量最高,但水提物高于醇提物。不论是水提物还是醇提物,不同生长期马齿苋茎中的多糖含量高于叶,而叶中的黄酮含量高于茎。在实验浓度范围内,两种溶剂提取物均有良好的抗氧化活性,随着提取物浓度的增加对羟基自由基（·OH）的清除能力增强,而对Ce（Ⅳ）的还原能力并不都是随浓度的增加而增强。在添加量为0.10~0.60 m L时,水提物对·OH的清除能力强于Vc,各个生长期马齿苋茎、叶水提物的抗氧化力强于醇提物,同一生长期茎对·OH的清除率都大于叶。添加量为0.50 m L时,水提物对Ce（Ⅳ）还原率最大的是花蕾期茎和盛花期叶达到79.64%。添加量为0.80 m L时,水提物对·OH的清除率最大的是花蕾期茎高达82.81%,醇提物对·OH的清除率最大的也是花蕾期茎为75.86%。
基金Supported by the National Natural Science Foundation of China (21106162)the National Key Natural Science Foundation of China (21136009)+1 种基金the National High Technology Research and Development Program of China (2009CB219904)the State Key Laboratory of Chemical Engineering (SKL-ChE-11A04)
文摘A novel polyglycidylmethacrylate(PGMA) microspheres with high adsorption capacity of Cr(VI) was prepared by cerium(IV) initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups.The micron-sized PGMA microspheres were prepared by a dispersion polym-erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups.The polymer microspheres were characterized by scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR).The results indicated that the polymer microspheres had an average diameter of 5 μm with uniform size distribution.The free amino group content was determined to be 5.13 mmol?g?1 for g-PGMA-NH2 mi-crospheres by potentiometric and conductometric titration methods.The Cr(VI) adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity(500 mg?g?1).The polymer microspheres with grafted tentacle polymer chains have poten-tial application in large-scale removal of Cr(VI) in aqueous solution.
