2017 Volume 23 Issue 1 Pages 111-118
Sedum aizoon is an edible medicinal plant with various pharmacological activities distributed widely in China. The flavonoids of S. aizoon have been shown to possess a variety of important biological activities. In this work, a microwave-assisted extraction (MAE) method was employed for the efficient extraction of flavonoids from S. aizoon leaves. The influences of MAE conditions including temperature, extraction time, solvent to solid ratio, and ethanol concentration on the yield of flavonoids were systematically investigated by single-factor experiments and response surface methodology (RSM) experimental design. Under the optimal MAE conditions of extraction time 20 min, extraction temperature 57°C, solvent to solid ratio 20 mL/g, and ethanol concentration 80.6%, the flavonoids yield reached 24.87 ± 0.26 mg/g and was much higher than that of conventional Soxhlet extraction (CSE) method (18.67 ± 0.35 mg/g). The obtained flavonoids exhibited strong antioxidant activities with IC50 value of 0.315 mg/mL in the DPPH radical-scavenging experients. The results indicated that MAE was a simple and efficient technology for the extraction of flavonoids from S. aizoon leaves and the flavonoids may serve as new potential natural antioxidant for functional food ingredients and additives.
