Deep Eutectic Solvent Based Microwave and Ultrasound Assisted Extraction of Bioactive Compounds From Vitex...

This study aimed to optimize microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) of bioactive compounds from the leaves of Vitex agnus-castus using deep eutectic solvents (DES). Response surface methodology (RSM) was applied to determine optimal extraction conditions. ChCl:TetEG:H₂O was selected as the optimal DES for MAE, while ChCl:TriEG:H₂O was identified as the most suitable solvent for UAE. The physicochemical properties of DES, including FTIR spectra, viscosity, pH, and density, were characterized. Optimal MAE conditions were predicted as a microwave power of 293 W, an extraction time of 119 s, and a liquid-to-solid (L/S) ratio of 25.12, whereas optimal UAE conditions were 501.96 W, 23.27 min, and an L/S ratio of 70.08. Antioxidant activities (TAC, DPPH, and ABTS) of DES extracts were compared with those obtained using 70% ethanol under optimal MAE and UAE conditions. Phenolic and flavonoid compounds were quantified by HPLC, including caffeic, syringic, p-coumaric, and ferulic acids, as well as rutin, myricetin, quercetin, and kaempferol. In addition, the antibacterial activities of the extracts were evaluated. The results demonstrate the effectiveness of optimized MAE and UAE combined with DES for the comprehensive recovery of bioactive compounds from Vitex agnus-castus.