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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%。
To study the antioxidant activity of extracts from leaves and stems of Portulaca oleracea at different growth stages. The stems and leaves of Portulaca oleracea at different growth stages were extracted with 70% ethanol and water, respectively. The content of polysaccharides and flavonoids in their extracts and aqueous extracts were determined by spectrophotometry. The anti-oxidative activity was tested in vitro. Pollen and flavone content in the stems of flowering Portulaca oleracea was the highest, but the water extract was higher than the alcohol extract. The content of polysaccharide in the stems of Portulaca oleracea in different growth stages was higher than that in leaves, and the content of flavonoids in leaves was higher than that of stems, no matter the water extract or alcohol extract. In the range of experimental concentration, the two solvent extracts had good antioxidant activity. With the increase of extract concentration, the scavenging capacity of hydroxyl radical (· OH) increased, while the reduction ability of Ce (Ⅳ) did not Both increase with increasing concentration. When the amount of added water was 0.10-0.60 m L, the scavenging ability of water extract to · OH was stronger than that of Vc. The antioxidant activity of water extracts of stem and leaf of Portulaca oleracea was higher than that of alcohol extracts in all growth stages. The clearance rate of · OH is greater than that of leaves. When the amount of added water was 0.50 m L, the maximum rate of Ce (Ⅳ) reduction was 79.64% at bud stage and flowering stage. The best removal rate of · OH by water extract was 82.81% at bud stage, and the highest · · OH scavenging rate was 75.86% at bud stage.