马齿苋黄酮抗氧化活性研究

为探讨马齿苋黄酮清除自由基、抑制油脂的脂质过氧化反应等体外抗氧化活性,分别采用Fenton体系法和邻苯三酚自氧化法及碘-硫代硫酸钠滴定法测定了马齿苋黄酮对羟基自由基、超氧阴离子的清除能力,以及对猪油氧化的抑制作用。结果表明,马齿苋黄酮对羟自由基、超氧阴离子有较好的清除效果。在供试浓度范围内对羟自由基的清除效率与黄酮浓度有一定量效关系,当黄酮浓度达0.56mg/ml时,清除率可达68.33%;而当黄酮浓度达0.56mg/ml时,对超氧阴离子的清除作用也最大,达82.26%。此外,马齿苋黄酮对油脂也表现出较强的抗氧化作用,可极显著地抑制猪油POV值的升高。

Study on Antioxidant Activity of Flavonoids from Portulaca oleracea L.

The antioxidant activities of flavonoid from Portulaca oleracea L.in vitro were discussed,such as scavenging the free radicals and inhibiting the lipid peroxidation of lipin.Fenton reaction,pyrogallic autoxidation and I_2-2Na_2S_2_O3 titration were used to determine its scavenging abilities on hydroxyl free radicals (·OH) and superoxide anion free radicals(O_2~-·) and inhibition on the oxidization of lard.Flavonoid from Portulaca oleracea L.had good scavenging effects on ·OH and O_2~-·.At the selected concentration,the scavenging effects on hydroxyl free radicals had certain dose dependent relationship with flavonoid concentration.When the concentration of flavonoid reached 0.56 mg/ml,the maximum scavenging rate on·OH was 68.33%.When the flavonoid concentration was 0.56 mg/ml,the maximum scavenging rate on O_2~-· was 82.26%.In addition,flavonoid from Portulaca oleracea L.also had strong antioxidative ability on lard.And it could inhibit POV of lard significantly.