Ultrasonic assisted extraction of Achyrocline satureioides Lam, D.C, (marcela) in aqueous media improves extraction yield and enhances selective bioactive extraction

This work studied ultrasound assisted extraction (UAE) as a green chemistry technique to improve aqueous extraction of bioactive compounds from marcela (Achyrocline satureioides Lam.), a native plant from South America with reported beneficial health effects. Dried intact marcela inflorescences were extracted using solely water as solvent in an ultrasonic bath, applying 100 and 150 W/L ultrasound power at 40 and 60 °C, respectively. Extraction was followed throughout 30 min by determining antioxidant capacity (AOC) and total polyphenol content (TPC) every 5 min. Extracts were analysed by LC-MS and LC-DAD to identify extracted bioactive compounds and analyse the impact of temperature and ultrasound application on compound profile. Solid-liquid extraction at 40 and 60 °C and maceration at room temperature were studied as reference extraction methods. UAE extracts were higher in AOC by 140% and 25% at 40 and 60 °C respectively, compared to solid-liquid extraction. For TPC, UAE showed an increase of 110% and 20% at 40 and 60 °C, respectively. LC results indicated that ultrasound application allowed faster and enhanced hydroxycinnamic acids extraction, whereas an increase in temperature resulted in a more diverse compound profile. UAE could be used to extract caffeic acid when applied at 40 °C.