大麻叶中总黄酮提取工艺的优化及其抗氧化活性测定

Optimization of Extraction Process for Total Flavonoids from Hemp Leaves and Their Antioxidant Activity Measure

为优化大麻叶总黄酮提取工艺并评估大麻叶总黄酮抗氧化活性,研究在单因素试验基础上,以提取时间、提取温度、料液比和乙醇体积分数为影响因素,总黄酮浸提量为评价指标,采用响应面试验设计优化提取工艺。采用FRAP总抗氧化能力测定试验、DPPH自由基清除试验以及ABTS自由基清除试验对总黄酮提取物进行抗氧化活性评价。结果表明:提取大麻叶总黄酮的最佳工艺条件为乙醇体积分数50%、料液比1∶20(g/m L)、提取时间2.0 h、提取温度70℃。在该最优提取条件下,大麻叶总黄酮浸提量为14.28 mg/g。抗氧化试验表明,大麻叶总黄酮的总抗氧化能力相当于1.288 mmol/L Fe SO4,对DPPH自由基的清除能力(IC50=3.7μg/m L)低于VC的清除能力(IC50=2.3μg/m L),而对ABTS自由基的清除力相当于0.391 mmol/L的Trolox。该工艺提取大麻叶得到的总黄酮含量较高,且具有一定的抗氧化性,可为未来大麻叶总黄酮的开发提供一定的科学依据。

In order to optimize the extraction process of total flavonoids from hemp( Cannabis sativa L.) and evaluate the antioxidant activity of total flavonoids,the response surface test was used in the research. With the extraction time,extraction temperature,solid-liquid ratio and ethanol volume fraction as the influencing factors,the total flavonoids extraction amount was used as the evaluation index. Meanwhile,the antioxidant activities of total flavonoids were investigated through the measurement of FRAP total antioxidant capacity,scavenging capacities on DPPH radical and ABTS radical. The results showed that the optimal extraction conditions were as follows: extraction time,2. 0 h;ethanol concentration,50%;solid-liquid ratio,1∶ 20( g/m L);temperature,70 °C. Under these conditions,the concentration of total flavonoids could reach 14. 28 mg/g. The total antioxidant capacity was equivalent to 1. 288 mmol/L Fe SO4. The IC50 on scavenging DPPH was 3. 7 μg/m L,which was lower than the scavenging capacities of VC. Meanwhile,the scavenging capacity on ABTS was equivalent to that of 0. 391 mmol/L Trolox. In conclusion,substantial total flavonoids could be obtained under optimal extraction conditions and had a certain antioxidant activity,which would provide reliable scientific instruction on the exploitation of total flavonoids in hemp leaves.