To reduce the environmental pollution caused by organic solvents and improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) was explored for the extraction of green tea polyphenols (TPs). The use of the NADESs, especially ChCl/EG (Choline chloride/Ethylene glycol, molar ratio 1:2), can increase extraction efficiency when comparing with the traditional solvents. Then response surface methodology (RSM) was used for the optimization of TPs extraction with ChCl/EG. The perfect regression prediction model was generated and the highest TPs extraction yield of 20.12% was achieved, highlighting the potential of NADES for TPs extraction.

Meanwhile, the applicability of COSMO-SAC (Conductor-like screening model for segment activity coefficient) for evaluation of TPs extractability in different solvents was investigated. Epigallocatechin gallate (EGCG) was employed as the TPs model solute. Geometry optimization and energy optimization of EGCG and these solvents were performed via COSMO-SAC. The extraction performance of the solvents was interpreted by the analysis of activity coefficient at infinite dilution (γ∞). The result showed that the higher the extraction yield, the lower the lnγ∞. The σ-profile and the interaction energy (E_INT) were generated to analyse the molecular interaction between solvent and solute. It was demonstrated that the combination of a strong hydrogen bond acceptor (HBA) - ChCl, with a relatively weaker hydrogen bond donor (HBD) - EG, resulted in a NADES (ChCl/EG) with a stronger affinity to TPs. This work provided both experimental and intermolecular insight to help choose effective solvent for bioactive components extraction in further research.

为了减少有机溶剂对环境的污染并提高提取效率，人们探索了一系列天然深共熔溶剂（NADES）来提取绿茶多酚（TP）。与传统溶剂相比，使用NADES，尤其是ChCl / EG（氯化氯/乙二醇，摩尔比为1：2）可以提高萃取效率。然后，将响应面方法（RSM）用于优化ChCl / EG萃取TPs。生成了完美的回归预测模型，并获得了最高的TPs提取率20.12％，突显了NADES在TPs提取中的潜力。

同时，研究了COSMO-SAC（段活度系数的类似导体的筛选模型）在不同溶剂中TPs萃取性评估中的适用性。表没食子儿茶素没食子酸酯（EGCG）用作TPs模型溶质。EGCG和这些溶剂的几何优化和能量优化是通过COSMO-SAC进行的。溶剂的提取性能通过活度系数的无限稀释（分析解释γ ∞）。结果表明，较高的提取率，较低的LN γ ∞。所述σ -profile和相互作用能（E _INT生成）分析溶剂和溶质之间的分子相互作用。结果表明，强氢键受体（HBA）-ChCl与相对较弱的氢键供体（HBD）-EG的结合产生了对TP具有更强亲和力的NADES（ChCl / EG）。这项工作提供了实验和分子间的见识，以帮助选择有效的溶剂用于生物活性成分的进一步提取。