Large quantities of agri-food by-products arise from citrus processing, creating disposal challenges but also opportunities for valorization. To address this, this study aimed to recover bioactive phenolics from C itrus aurantium leaves (CAL) and to define their composition and bioactivity. First, was screened 16 ionic liquids and identified 1-hexyl-3-methylimidazolium chloride ([C 6 mim]Cl) as the optimal-polarity solvent for phenolic extraction. Building on this, an ionic liquid–ultrasound synergistic extraction (IL–USE) process was developed and optimized using single-factor experiments combined with response surface methodology. Under the optimal conditions (0.35 mol/L [C 6 mim]Cl, liquid-to-solid ratio 27 mL/g, ultrasonic power 280 W, 50 min, 55 °C), the total phenolics yield reached 80.57 ± 0.60 mg/g. Compared with ultrasound-assisted extraction and conventional heat-reflux extraction, IL-USE delivered higher yields. This enhancement was macroscopically reflected in the scanning electron microscopy (SEM) analysis, which revealed more pronounced cell-wall disruption. For downstream enrichment, among five macroporous resins evaluated, HPD-826 performed best, and subsequent optimization of breakthrough and elution parameters afforded a CAL total phenolics (CAL-TP) fraction with 77.45 ± 1.63% purity. Furthermore, UPLC-QTOF-MS/MS tentatively identified 47 constituents, establishing a robust chemical profile of CAL-TP. Functionally, in insulin-resistant HepG2 cells, CAL-TP increased glucose consumption and glycogen synthesis and enhanced hexokinase and pyruvate kinase activities, thereby indicating hypoglycemic potential. Collectively, this study provides a green and efficient process that yields phenolic-rich fractions from CAL with defined composition and promising antidiabetic activity.
A molecularly imprinted polymer (MIPs) was prepared based on a computer-aided design, which was used to selectively enrich and purify synephrine (SYN) from the extract waste liquid of Citrus aurantium L. The suitable functional monomers , cross-linkers and reaction systems for preparing MIPs were quickly screened with density functional theory (DFT) calculation to effectively avoid the design blindness of molecularly imprinted material. The synephrine molecularly imprinted polymer (SYN-MIPs) with imprinted holes and magnetic properties were prepared with nano Fe 3 O 4 as the core, and the structure, morphology, magnetic property and adsorption behavior were studied and the interaction mechanism of the adsorption process was clarified by DFT calculations. The saturated adsorption of SYN-MIPs for SYN was as high as 47.38–53.68 mg/g within 298 K to 308 K. The adsorption behavior of SYN-MIPs for SYN was well fit for the Freundlich adsorption and the pseudo-second-order kinetic model. It was worth mentioning that SYN-MIPs showed distinguished re-usability and specific recognition. The imprinting factor and selection factor to SYN were 3.13 and 2.43, respectively. The selective enrichment and purification of SYN from the extract waste liquid of Citrus aurantium L. achieved satisfactirily, and the purity of SYN enriched to 93.73% while the concentration of SYN was only 1.73% in the extract waste liquid. The study provides not only an efficient adsorption separation polymer materials but also a practical for the enrichment and purification process of SYN from the extract waste liquid of citrus plants.
危险品化学品经营许可证（带存储）