酶法-超声提取黄精总黄酮及其抗氧化活性研究

Study on Enzymatic-ultrasonic Assisted Extraction of Total Flavonoids from Polygonatum Sibirici and Its Antioxidant Activities

关键词:  黄精  总黄酮  纤维素酶  超声波  提取工艺  抗氧化活性

Key words:  Polygonatum sibiricum  total flavonoids  cellulase  ultrasonic  extraction technology  antioxidant activity

摘要:

目的 研究酶法-超声提取黄精中总黄酮（total flavonoids from Polygonatum sibirici，TFPS）的最佳工艺及总黄酮的体外抗氧化活性。方法 以总黄酮含量为指标，采用单因素和正交试验对纤维素酶用量、乙醇浓度、液料比和超声时间进行考察，优化工艺条件并考察总黄酮对DPPH自由基、ABTS⁺自由基的清除能力和亚铁离子螯合活性。结果 最佳提取条件：纤维素酶用量为0.75%，乙醇浓度为40%，液料比为20 mL·g^-1，超声时间30 min，总黄酮含量为1.595%。体外抗氧化试验表明，黄精总黄酮对DPPH自由基、ABTS⁺自由基有很强的清除能力，IC₅₀分别为27.55，11.47 μg·mL^-1，对亚铁离子的螯合活性较强，IC₅₀为32.26 μg·mL^-1。结论 酶法-超声提取工艺具有提取效率高、稳定性及重复性好等优点，可用于黄精中总黄酮的提取，在该工艺下提取的总黄酮具有较强的抗氧化活性。

Abstract:

OBJECTIVE To study the optimum extraction technology for the total flavonoids from Polygonatum sibiricum(TFPS) by enzymatic-ultrasonic method, and to research its antioxidant activities. METHODS Using total flavonoids compounds as investigation indexes, single factor and orthogonal test were used to investigate the cellulase amount, ethanol concentration, liquid-solid ratio and ultrasonic time, and the extraction technology was optimized. Furthermore, the antioxidant activities of TFPS were evaluated, using various antioxidant assays included the scavenging on DPPH, ABTS⁺ and ferrous ion-chelating capacity. RESULTS The optimum extraction conditions were as follows:cellulase amount was 0.75%, ethanol concentration was 40%, liquid-solid ratio was 20 mL·g^-1, ultrasonic time was 30 min, and extraction rate of total flavonoids was 1.595%. TFPS had strong scavenging activity on ·DPPH and ABTS⁺ free radicals, the IC₅₀ was 27.55, 11.47 μg·mL^-1, and also had strong ferrous ion-chelating capacity, the IC₅₀ was 32.26 μg·mL^-1. CONCLUSION The enzymatic-ultrasonic method is stable, feasible and has the advantage of high extraction efficiency, and can be used for the extraction of TFPS. These results show that TFPS has strong antioxidant activity under the optimal extraction technology.