Résumé
Objective:To optimize the extraction technology and evaluate antioxidant activity of total flavonoids from Hedyotis dif-fusa. Methods:The content of kaempferol was detected by an HPLC method,and spectrophotometry was used to detect the content of total flavonoids. Results: The optimum extraction conditions were investigated by orthogonal design with the extraction quantities of kaempferol and total flavonoids as the evaluation indices. The antioxidant activities of the extracts were detected based on the clearance of hydroxyl radical and DPPH·model. The optimum extraction conditions were as follows:10-fold amount of 80% methanol and with ultrasonic extraction for 15 min. The clearance rate of 1ml methanol extract for scavenging DPPH· and ·OH was 73.89% and 91.27%,respectively.Conclusion:The optimum technology is stable and feasible for the extraction of Hedyotis diffuse. The extract shows good in vitro antioxidant properties, which provides powerful reference for the future development of relevant antioxidant prod-ucts.