泉州湾湿地南方碱蓬种子水提物总黄酮含量及其抗氧化能力评价

Total Flavonoid Content of Aqueous Extracts from Suaeda australis Seeds in Quanzhou Bay Wetlands and Assessment of Its Antioxidant Activity

以聚酰胺吸附—硝酸铝显色法测定泉州湾湿地南方碱蓬(Suaeda australis)种子水提物的总黄酮含量,并测定评价其在羟基自由基体系、二苯代苦肼自由基(DPPH·)体系、超氧阴离子自由基体系中的抗氧化活性。结果表明,南方碱蓬种子水提物得率为18.49%;水提物的总黄酮含量为2.74%,显著大于95%乙醇提取物(1.94%)、丙酮提取物(0.62%)、乙酸乙酯提取物(0.51%)、甲醇提取物(0.37%)和石油醚提取物(0.10%)的总黄酮含量。在不同的自由基体系中,南方碱蓬种子水提物对超氧阴离子自由基的清除作用相对很弱,在水提物的浓度为153mg/mL时,清除率仅为30%;但其对羟基自由基的清除能力较强,在施测浓度为20mg/mL时,水提物对羟基自由基的清除率达79.50%,弱于95%乙醇提物(90.98%),强于乙酸乙酯提物(70.35%)、丙酮提物(68.40%)、甲醇提物(65.50%)和石油醚提物(63.18%),其半效应浓度为0.53mg/mL;水提物对二苯代苦肼自由基的清除呈现明显的量效关系,当水提物浓度为200mg/mL时,对二苯代苦肼自由基的清除率可达92.44%,其半效应浓度为57.56mg/mL。可见,南方碱蓬种子水提物具有较高的总黄酮含量和一定的抗氧化能力,具有作为植物源抗氧化剂开发的潜在价值。

Aim to exploit Suaeda australis seeds in Quanzhou Bay wetlands as antioxidants from plant sources, the content of total flavonoid of aqueous extract from Suaeda australis seeds was determined by the polycaprolactan purifying-aluminium nitrate color reaction method and the antioxidant activities of aqueous extract were studied by the assays system of 1, 1-diphenyl-2-picrylhydrazyl free radical, hydroxyl free radical, super oxide anion free radical. The results showed that the obtaining ratio of aqueous extracts from Suaeda australis seeds was 18.49% and the content of total flavones in aqueous extracts was 2.74%, which was significantly higher than the total flavonoid content of 95% ethanol extract （1.94%）, acetone extract （0.62%）, ethyl acetate extract （0.51%）, methanol extract （0.37%） and petroleum ether extract （0.10%） respectively. In the different free radical systems, aqueous extract had weaker action in the super oxide anion free radical system, the scavenging rate was only 30% when the concentration of aqueous extract was 153 mg/mL, but it showed stronger scavenging activity against hydroxyl free radical, when the concentration of aqueous extract was 20mg/mL, its scavenging rate against hydroxyl free radical reached 79.50%, which was lower than that of 95% ethanol extract （90.98%） but higher than that of ethyl acetate extract （70.35%）, acetone extract （68.40%）, methanol extract （65.50%） and petroleum ether extract （63.18%） respectively, its semi-inhibitory concentration against hydroxyl free radical was about 0.53 mg/mL. The results also showed that there was obvious quantity-efficiency relation between the concentration of aqueous extract and its scavenging rate against 1, 1-diphenyl-2-picrylhydrazyl free radical, the scavenging rate of 200 mg/mL aqueous extract reached 92.44%, the semi-inhibitory concentration against 1, 1-diphenyl-2-picrylhydrazyl free radical was 57.56 mg/mL. Therefore, aqueous extracts from Suaeda australis seeds had higher total flavonoid content and some antioxidant activity. It could be a potential kind of antioxidants from plant sources.