Ecofriendly Mechanochemical Extraction of Bioactive Compounds from Plants with Deep Eutectic Solvents

A fast, highly efficient, and ecofriendly extraction method using deep eutectic solvents (DESs) for mechanochemical extraction (MCE) was developed to extract bioactive compounds from plants. Tea leaves containing bioactive compounds such as alkaloids, flavonoids, and catechins were used to evaluate this method. Dozens of DESs and DESs/water mixtures were systematically studied and optimized to select optimized extraction conditions. The results showed that the extractions can be completed within 20 s. Moreover, the developed extraction method is more ecofriendly, faster, gentler, and more efficient than conventional methods. For many compounds, we could simply use the described method without optimization. On the other hand, the target compounds were extracted with various interferences because of the wide ranging high extraction efficiency. Ultrahigh performance liquid chromatography coupled with high-resolution mass spectrometry was therefore used for qualitative and quantitative analysis to characterize the efficiency for individual compounds. To avoid the negative effect of DESs on chromatographic separation, the analytical performances of this method, including reproducibility (RSD, n = 5), correlation of determination (r2), and the limit of detection, were determined.