白背三七黄酮类化合物的提取及抗氧化性评价

Extraction and ontioxidant evaluation of flavonoids from Gynura divaricata (L.) DC. leaves

采用乙醇提取法从白背三七叶中提取具有生物活性的黄酮类化合物,并对其抗氧化活性进行综合评价。通过正交试验,确定了白背三七黄酮类化合物提取的最优工艺条件:乙醇体积分数80%,料液比1∶25(质量体积比),提取温度65℃,提取时间120 min。在此条件下,黄酮类化合物平均得率3.81%;抗氧化试验结果表明白背三七黄酮类化合物具有较强的抗氧化能力,且呈明显的剂量效应。对Fe3+的还原能力与VC接近(P>0.05),而远高于BHT;对DPPH自由基和ABTS自由基均具有很好的清除效果,其IC50值分别为0.039 mg/ml和0.062 mg/ml。白背三七黄酮类化合物对DPPH自由基的清除能力极显著高于对照组BHT和VC(P<0.01),对ABTS自由基清除能力显著强于VC,但不如BHT。

Flavonoids with biological activity were extracted from Gynura divaricate (L.) DC. leaves by ethanol method, and their antioxidant activities were evaluated comprehensively. The extraction technique was optimized using orthogonal experiments, and the optimum extraction parameters were as follows: ethanol concentration 80%, material-liquid ratio 1∶ 25, extracting temperature 65 ℃, extracting time 120 min, and under these conditions, the yield of flavonoids was 3.81%. The results of antioxidant test showed that the flavonoids had strong antioxidant capacity and obvious dose effect ability of Fe 3+ was close to that of V C ( P >0.05), but much higher than that of BHT. The ability of scavenging DPPH and ABTS free radical was strong, and their IC 50 values were 0.039 mg/ml and 0.062 mg/ml , respectively. The scavenging ability of DPPH radical was significantly higher than that of BHT and V C ( P <0.01), and the scavenging ability of ABTS radical was significantly stronger than that of V C , but not as good as that of BHT.