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• Deep eutectic solvent (DES) was used to distillate essential oil (EO). • DES-homogenate based microwave-assisted hydrodistillation was developed. • m -Cymene and trans -linalool oxide were the major components of Litsea cubeba EO. • Higher isolation efficiency and antioxidant activity of EO were obtained. As an important natural product, the sufficient separation of plant essential oil (EO) is helpful to improve its utilization value. In this work, deep eutectic solvent-homogenate based microwave-assisted hydrodistillation (DES-HMAHD) was developed and applied to isolate EO from the fruits of Litsea cubeba (Lour.) Pers. Different types of DES were investigated in terms of the EO kinetics and composition, among which oxalic acid/choline chloride (OA/ChCl) had obvious advantages. Following, molar ratio of OA and ChCl (1:1), water content (50%), liquid-solid ratio (12.5:1 mL/g), homogenate time (2 min), and microwave power (700 W) were found to be the optimum conditions. Gas chromatography-mass spectrometer (GC-MS) analysis showed that the EO isolated from DES-HMAHD contained a large proportion of m -cymene and trans -linalool oxide, which were quite different from the conventionally reported L. cubeba EO. In addition, the proposed DES-HMAHD resulted in higher separation efficiency and economic value, as well as lower environmental impact, as compared with other techniques. Afterwards, the EO isolated by different methods was evaluated from the perspective of biological activity. The EO obtained by DES-HMAHD showed higher antioxidant activity (DPPH and ABTS) but lower antifungal activity, which was related to its chemical composition. In general, DES-HMAHD produced a kind of L. cubeba EO with different components, which provided a scientific foundation for the sufficient isolation of plant EO and its application in the natural products. [ABSTRACT FROM AUTHOR]

• Enzyme-ultrasonic pretreatment promotes the efficient isolation of essential oil. • Enzyme, ultrasound, and microwave affect the essential oil kinetic and composition. • A higher proportion of oxygenated components is obtained after pretreatment. • Artemisia argyi essential oil has excellent antioxidant and antifungal activity. The in-depth study of plant essential oil (EO) to provide valuable resources for the development of natural medicinal products is one of the current research hotspots. The present work realized the efficient isolation of EO from Artemisia argyi leaves using aqueous enzyme-ultrasonic pretreatment followed by microwave-assisted hydrodistillation (EUP-MHD). Because of the synergistic reaction mechanism, the combination of enzyme and ultrasound doubly improved the separation of EO. After the optimization process (single factor experiments, Plackett–Burman design, and Box–Behnken design), mixed enzyme (cellulose + pectinase + papain), concentration of 10 U/mg, ultrasonic frequency of 45 kHz, ultrasonic power of 200 W, ultrasonic time of 20 min, reaction temperature of 50 °C, pH of 5, microwave power of 650 W, microwave time of 10 min, and liquid-solid ratio of 10 mL/g performed best, with the yield of EO of 5.32 ± 0.20 mg/g. A distinct advantage of this technique was found as compared with other techniques, which highlighted the positive influence of the pretreatment process. Additionally, the oxygenated components of EO from EUP-MHD accounted for a higher proportion than other methods, including eucalyptol, borneol, camphor, neointermedeol, and terpinen-4-ol. Finally, the evaluation of the biological activity of A. argyi EO pointed out that the EO had excellent antioxidant activity and higher inhibitory activity against Phytophthora capsica but presented weaker cytotoxic activity. In general, the technique used in this study is promising in the field of separating EO from crop materials. [ABSTRACT FROM AUTHOR]