超声提取香青兰中黄酮及其抗氧化活性

研究香青兰中总黄酮超声提取工艺及其抗氧化活性。在单因素试验的基础上设计正交试验，用分光光度法测定香青兰总黄酮清除自由基的能力和还原力并与VC做比较。超声提取香青兰中总黄酮最佳工艺为乙醇体积分数60%、超声提取时间50min、提取温度60℃、料液比1:40(g/mL)，此时黄酮得率为1.89%。香青兰黄酮的还原力比VC约大1倍，对羟自由基、DPPH自由基和超氧阴离子自由基的半抑制浓度(IC50)分别为35.6、9.6μg/mL和56.0μg/mL。香青兰总黄酮具有较强的抗氧化活性，且存在明显的量效关系。

Ultrasonic-Assisted Extraction and Antioxidant Activity of Flavonoids from Dracoephalum mololarie L.

In this study we investigated the ultrasonic-assisted extraction and antioxidant activity of fl avonoids from the aboveground part of Dracoephalum mololarie L. An orthogonal array design was used to optimize the extraction process. Flavonoid extract was determined spectrometrically for free radical scavenging activity and reducing power and compared with VC. The optimum conditions for extracting flavonoids from the above-ground part of Dracoephalum mololarie L. were determined as 60% ethanol as an extraction solvent at a solid-to-solvent of 1:40 (g/mL), 50 min of ultrasonic treatment time and 60 ℃ of extraction temperature. Under these conditions, the fl avonoid yield was 1.89%. The reducing power of the fl avoniod extract obtained was approximately 2-fold higher than that of VC, and its IC50 values in hydroxyl, DPPH and superoxide anion assays were 35.6, 9.6 μg/mL and 56.0 μg/mL, respectively. Moreover, this extract had potent antioxidant activity in a dose-dependent manner.