Ultrasound-Assisted Extraction of Plant Compounds

The extraction method was conducted by adapting the procedures described by De Montijo-Prieto et al. [34 (link)] with slight modifications. For this purpose, previously ground plant material was accurately weighed (0.1 g) and mixed with 5 mL of an 80% methanol/water solution v/v. Extraction was conducted in an ultrasonic bath (Emmi 20 HC, EMAG, Salach, Germany) at 40 °C for 15 min. Every 5 min, the samples were vortexed with a Vortex Mixer (Velp Scientifica, Usmate Velate, Italy) for 15 s. Next, the extracts were centrifuged for 10 min at 9000 rpm. Following this step, the extraction with the solvent was repeated two more times, each time collecting the supernatant. Then, the supernatants were combined and evaporated under reduced pressure.