Switchable deep eutectic solvents (SDESs) have recently been developed to improve the recovery and reuse of the extractants. In this work, temperature-induced SDESs were prepared and used for the extraction of flavonoids (representative phlorizin and trilobatin) from sweet tea ( Lithocarpus litseifolius (Hance) Chun). These SDESs solution can switch between solution and sediment depending on the temperature, and the phase diagram of SDESs solution had been drawn. Their temperature-responsive characteristics were studied by various characterizations, including variable-temperature FT-IR, variable-temperature 1 H NMR, and variable-temperature dynamic light scattering (DLS). SDES-1 (Benzamide: Malic acid = 2:1) was screened as the optimal extractant, and the major factors affecting the extraction process were studied by single-factor experiments and optimized by response surface methodology (RSM). The extraction yields for phlorizin and trilobatin were 114.72 and 12.56 mg/g, respectively. Moreover, the recoveries for phlorizin and trilobatin reached 98.46 % and 94.64 %, respectively. This study thus provides an environmentally sound strategy for extracting bioactive compounds from plant resources.
Yujuan Zhang,Ziwen Luo,Dongmei Wang,Fengyuan He,Dengwu Li
The ethanol crude extracts (ECE) and their subfractions from Zanthoxylum bungeanum leaves were prepared and their phytochemical profiles and antioxidant and antimicrobial activities were investigated. Moreover, the effective HPLC procedure for simultaneous quantification of twelve compounds in Z. bungeanum leaves was established. The correlation between the phytochemicals and antioxidant activity was also discussed. The ethyl acetate fraction (EAF) had the highest total phenolic (97.29 mmol GAE/100 g) and flavonoid content (67.93 mmol QE/100 g), while the greatest total alkaloid content (4.39 mmol GAE/100 g) was observed in the chloroform fraction (CF). Twelve compounds were quantified by RP-HPLC assay. EAF exhibited the highest content of quercitrin, kaempferol-3-rhamnoside, quercetin, sesamin, and nitidine chloride (125.21, 54.95, 24.36, 26.24, and 0.20 mg/g); acetone fraction (AF) contained the highest content of chlorogenic acid, rutin, hyperoside, and trifolin (5.87, 29.94, 98.33, and 31.24 mg/g), while kaempferol-3-rhamnoside, xanthyletin, and sesamin were rich in CF. EAF and AF exhibited significant DPPH, ABTS radical scavenging abilities and reducing power (FRAP), whereas CF exhibited significant antifungal activity. Moreover, EAF also showed stronger antibacterial activity. In conclusion, Z. bungeanum leaves have health benefits when consumed and could be served as an accessible source for production of functional food ingredients and medicinal exploration.
危险品化学品经营许可证（带存储）