天山雪菊不同溶剂提取物的抗氧化活性研究

以天山雪菊为原料,经过超临界二氧化碳萃取后,萃余物又分别采用丙酮、体积分数分别为50%、95%乙醇进行提取,获得不同溶剂提取的4种天山雪菊提取物,比较不同溶剂提取物的抗氧化活性。通过对二苯基苦基苯肼(DPPH)自由基和羟基自由基清除能力的评价,比较各种提取物的抗氧化活性,并对各种提取物中的总多酚和总黄酮的含量进行了分析。结果表明,4种提取物对DPPH自由基均具有较强清除活性,但活性弱于对照品二丁基羟基甲苯(BHT)、水溶性维生素E(Trolox)、α-生育酚和Vc;对羟基自由基的清除能力低于对照品芦丁和BHT。清除DPPH自由基的能力以体积分数为50%乙醇提取物最强,超临界浸膏最弱;清除羟基自由基的活性以体积分数为50%乙醇提取物最强,丙酮提取物最弱。

Antioxidant activity of different solvent extracts from Coreopsis tinctoria

To compare the antioxidant activity of different solvent extracts from Coreopsis tinctoria, the C. tinctoria sample was extracted by super- critical CO2 extraction, and then the residue was extracted by acetone, followed by 95% ethanol and 50% ethanol, respectively. Four kinds of C. tinc- toria solvent extracts were obtained and the antioxidant activity was evaluated. The DPPH free radical scavenging activity and hydroxyl radical scav- enging activity were evaluated and the content of flavonoids and polyphenols were analyzed for comparison. The results showed that all those extracts had strong antioxidant activity on DPPH free radicals, but all lower than the activities of butylated hydroxytoluene（BHT）, trolox, tz-tocopherol and vi- tamin C. The antioxidant activity of extracts on hydroxyl free radical was lower than rutin and BHT. Among the extracts, the one extracted by 50% ethanol had the highest antioxidant activity on DPPH free radicals; however, the one extracted by supercritical CO2 extraction had the lowest activity. In addition, the one extracted by 50% ethanol had the highest antioxidant activity on hydroxyl free radicals, and the one extracted by acetone had the lowest activity.