Simultaneous optimization of ultrasound-assisted extraction of flavonoid compounds and antiradical activity from...

Artemisia herba-alba (Aha) is an aromatic and medicinal plant rich in health-promoting flavonoids compounds that play an important role as antioxidant. For better utilization of this resource, the ultrasound-assisted extraction (UAE) of flavonoids and antiradical activities of obtained extracts from Aha using response surface methodology was assessed. A four-factor five-level central composite rotatable design was employed to discuss these extracting parameters: ethanol concentration (X1), temperature (X2), extraction time (X3) and solvent to sample ratio (X4). The optimum extraction conditions for simultaneous maximization of total flavonoids (TF) and scavenging activity were solvent concentration of 50%, temperature of 55 °C, extraction time of 50 min and solvent to sample ratio of 90 mL/g. Under these conditions, the experimental yield of TF and DPPH-radical scavenging activity IC_50% were respectively 102.49 mg CE/g DM and 7 µg/mL. Additionally, good and moderate linear correlation was observed between antiradical activity and TF content (R² = 0.709) which indicated that these compounds are responsible for antioxidant activity of Aha. When compared to the most conventional extraction, antioxidant activity and amounts of major flavonoids are enhanced when using UAE with reduced extraction time.