线叶旋覆花总黄酮的提取工艺优化及其抗氧化活性分析

采用响应面法优化线叶旋覆花总黄酮的提取工艺,评价最佳条件下得到提取物的抗氧化活性。以线叶旋覆花总黄酮提取量为指标,考察乙醇体积分数、提取温度、液料比、提取时间对总黄酮提取量的影响。在单因素试验的基础上,采用4因素3水平的响应面法确定线叶旋覆花总黄酮的提取工艺。结果表明,线叶旋覆花总黄酮提取的最佳工艺为:乙醇体积分数70%、提取温度87℃、液料比31:1 mL/g、提取时间40 min,线叶旋覆花总黄酮提取量为(33.62±0.0207) mg/g。最佳工艺条件下得到的提取物对1,1-二苯基-2-苦基肼自由基(IC₅₀=0.074 mg/mL)的清除能力强于V_C(IC₅₀=0.082 mg/mL),但对OH·的清除能力明显弱于V_C。响应面法优化线叶旋覆花总黄酮提取工艺切实可行,得到的总黄酮有较强的抗氧化活性,为线叶旋覆花总黄酮的开发提供理论依据。

Optimization of Extraction Process of Total Flavonoids from Inula lineariifolia and Its Antioxidant Activity

The optimization of the extraction process of total flavonoids from Inula lineariifolia was achieved by response surface methodology and its antioxidant activity were evaluated. The yield of total flavonoids was taken as the index to study the effect of ethanol concentration,extracting temperature,liquid/solid ratio and extracting time. Based on the single factor experiments,the four factors and three levels of response surface analysis method was taken to determine the extraction of total flavonoids from Inula lineariifolia. The results showed that the optimum extraction conditions were as follows:Ethanol concentration 70%,extracting temperature 87 ℃,liquid-solid ratio 31:1 mL/g,extracting time 40 min. Under the conditions,the yield of total flavonoids was(33.62±0.0207) mg/g. The scavenging ability of total flavonoids from Inula lineariifolia on DPPH radical(IC₅₀=0.074 mg/mL)was stronger than that of V_C(IC₅₀=0.082 mg/mL),but the scavenging ability of hydroxyl radical was obviously weaker than V_C. The extraction process of total flavonoids from Inula lineariifolia which optimized by response surface methodology was stable and practicable. Moreover,the total flavonoids obtained under optimum extraction conditions had strong antioxidant activity,which provided a theoretical basis for the development of total flavonoids from Inula lineariifolia.