Ultrasonic-assisted extraction of phenolic compounds from Paederia pilifera Hook. f. leaves and its antioxidant activity

Effect of ultrasonic-assisted extraction of phenolic compounds from Paederia pilifera Hook. f. leaves was investigated. In the extraction process, 3 main parameters: ethanol concentration, extraction temperature and extraction time were used to determine the optimal extraction condition of phenolic compounds from the sample. It was found that the extraction of sample with 70% (v/v) ethanol at 50 ºC for 60 minutes gave the highest total phenolic content (129.89 µg GAE/g). The antioxidant activities of crude extract from the optimal extraction condition was further investigated by 2 radical scavenging assays namely, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The results revealed that the crude extract exhibited relatively high antioxidant activities with IC50 values of 2.16 mg/ml by DPPH, and 2.14 mg/ml by ABTS methods, respectively.