红檵木花叶的总黄酮含量与抗氧化活性差异

Differences of Flavonoids Contents and Antioxidant Activities from Flowers and Leaves of Loropetalum chinense

为更好地开发利用红檵木,采用乙醇浸提的方法获得红檵木嫩叶、老叶及花中的总黄酮,并测定其黄酮含量和总抗氧化活性,以及清除超氧阴离子、羟基自由基和DPPH自由基的能力。结果表明：红檵木花、嫩叶和老叶中的总黄酮含量分别为7.44%、4.75%、3.82%。各部位醇提物浓度在0.00-0.35mg/mL时,均有抗氧化活性,花的活性最高;浓度在0.0-0.4mg/mL时,抑制邻苯三酚自氧化速率和羟基自由基的清除率低于20%;当浓度大于1.5μg/mL时,对DPPH的清除率均大于50%,老叶在7.5μg/mL时的清除率可达90%,各部位均表现出一定的抗氧化活性,且随浓度的增加,抗氧化能力增强。

To preferably develop and utilize L.chinense,total flavonoids were gained from tender leaves,old leaves and flowers by ethanol extraction method,then the flavonoid content and antioxidant activities were detected,as well as the scavenging activity of superoxide anion,hydroxyl radical and DPPH radical.Results：Total flavonoid contents were respectively 7.44%,4.75%and 3.82%in flowers,tender leaves and old leaves,which was the highest in flowers.Antioxidant activity could be detected when the concentration was 0-0.35mm/mL,and it was the highest in flowers;The scavenging rate of pyrogallic acid and hydroxyl radical was lower than 20% when the concentration was 0-0.4 mg/mL;Scavenging rate of DPPH radical was over 50% when the concentration was over 1.5μg/mL,and it could be over 90%when the concentration was 7.5μg/mL in old leaves,antioxidant activity appeared in various parts,and it increased with concentration increasing.