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.