鸭跖草总黄酮的提取工艺及抗氧化性研究

研究鸭跖草总黄酮的提取工艺和体外抗氧化能力.通过四种单因素试验，优选设计鸭跖草总黄酮提取正交实验方案，以Vc为对照，测定鸭跖草总黄酮清除超氧阴离子自由基、DPPH自由基、羟自由基的能力.结果表明：用60%的乙醇在60℃下以料液比1：30提取3h的条件为最佳工艺组合，总黄酮得率为34.32mg/g；鸭跖草总黄酮对3种自由基的清除效率与质量浓度呈正相关，其对超氧阴离子自由基和 DPPH 自由基的清除效果较好，且对DPPH自由基的清除作用最强，略低于 Vc，对超氧阴离子自由基的清除能力与 Vc相当，对羟自由基的清除能力低于Vc.

Study on the Extraction Conditions and Antioxidant Capacity of Total Flavonoids of Commelina communis L.

To optimize the condition of extraction for total flavonoids in Commelina communis L. and study its antioxidant capacity. Based on the single-factor experiment, the best conditions of extracting total flavonoids were optimized by orthogonal test. Compared with Vc, the antioxidant effects of the total flavonoids were evaluated by using superoxide radical （O2-·） scavenging assay, DPPH radical （DPPH·） scavenging assay, and hydroxyl radical （·OH） scavenging assay. The results showed that the optimal extraction conditions were determined as follows：60% ethanol as the extraction solvent, the ratio of material to liquid 1：30, 3h extraction time and 60℃temperature. Under these conditions, the extraction yield of total flavonoids of Commelina communis L. was 34.32mg/g. The radical scavenging efficiency was enhanced with the increasing flavonoid concentration. The total flavonoids had better scavenging effect on removing DPPH· and O2-·. Moreover, it had the strongest scavenging ability on removing DPPH·, slightly lower than Vc, equal on removing O2-· to Vc,and lower on removing ·OH than Vc.