铁甲草提取物的体外抗氧化活性

The anti-oxidant activities of Cassia mimosoides extracts

用95%乙醇超声提取铁甲草抗氧化有效成分,旋转蒸发至膏状,用蒸馏水溶解,然后用石油醚、氯仿、乙酸乙酯和正丁醇萃取,测定其不同萃取液的抗氧化活性指标。用(亚硝酸钠-硝酸铝-氢氧化钠)分光光度法测定提取液的总黄酮含量和福林-酚试剂法测定总酚含量,用二苯代苦味酰基自由基法检测提取液自由基清除活性,铁离子还原法(FRAP值法)检测提取液总还原力的大小。通过液相色谱初步分离各提取萃取物。采用加热氧化实验法,以过氧化值和酸值为指标检测提取物对鲜榨花生油的抗氧化效果。结果表明,铁甲草有较强的抗氧化活性,其中乙酸乙酯萃取液黄酮和酚类含量高,其对DPPH清除能力也较好,对油脂的过氧化值有明显影响。用乙酸乙酯能对铁甲草醇提溶物中的抗氧化物质进行有选择的分离富集,具有一定的实际应用价值。

Cassia mimosoides is commonly used in Hakka area as Chinese herb. The whole plants of Cassia mimosoides were extracted by 95% ethanol, and then the dry crude extaction was extracted sequentially with petroleum ether, chloroform, ethyl acetate and butanol, respectively. We investigated the anti-oxidant activity of all the extract by two in vitro assays, namely DPPH radical-scavenging activity and ferric reducing/antioxidant power （FRAP） assay. The content of total flavonoids and total phenols were measured by aluminum chloride and Folin-Ciocalteu colorimetric assays, respectively. The compounds were isolated from the extraction of Cassia mimosoides preliminarily by HPLC. The anti-oxidant activity of the extract was studied by Schaal experiment according to POV （peroxide value） of fresh peanut oil. The results showed that extract had strong anti-oxidant activity in the systems tested on the whole. The extract by ethyl acetate had distinctly higher value of anti-oxidant activity than the others. Thus, we suggested that extract by ethyl acetate could be used as potential sources of safe dietary supplement or antioxidant of natural origin to promote human health.