Chen Kangni, Troise Antonio Dario, Bunschoten Anton, De Pascale Sabrina, Scaloni Andrea, Fogliano Vincenzo, Madadlou Ashkan
Food Quality and Design Group, Wageningen University & Research, 6708WG Wageningen, The Netherlands.
Proteomics, Metabolomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80055 Portici, Italy.
ACS Sustain Chem Eng. 2025 Jul 21;13(30):11898-11912. doi: 10.1021/acssuschemeng.5c03053. eCollection 2025 Aug 4.
Despite the growing interest in natural deep eutectic solvents (NADESs) for green separation, critical aspects of their structural stability in aqueous two-phase systems (ATPS), solute partitioning mechanisms, and potential as reaction media remain poorly understood. This study investigates the development and application of NADES-KHPO ATPS. Four NADES formulations, namely, betaine-glycerol (Bet:Gly), betaine-propylene glycol (Bet:PG), choline chloride-glycerol (ChCl:Gly), and choline chloride-propylene glycol (ChCl:PG), were synthesized and characterized using H NMR and differential scanning calorimetry (DSC). The phase-forming ability of the NADES-KHPO ATPS was influenced by the hydrophobicity of the NADES; specifically, the Bet:PG formulation required the lowest KHPO concentration (25.1 wt %) for phase separation. In these systems, the hydrophobic NADES-rich phase preferentially partitioned hydrophobic amino acids (e.g., phenylalanine, > 100; alanine, ≈ 10), while glucose was enriched in the KHPO-rich phase ( ≈ 0.03). DSC analysis confirmed that the NADESs retained their structural integrity within the ATPSs. The Maillard reactions were performed in Bet:PG-KHPO ATPSs under strongly alkaline conditions (pH 11.65 in the top phase and 11.34 in the bottom phase) at 37 °C. Results demonstrated that Bet:PG enhances the formation and stabilization of the Amadori compounds through hydrogen-bonding and restricted molecular mobility. Overall, this work demonstrates that NADESs retain their supramolecular structure within ATPSs, enabling their dual functionality as both selective extractants and microreactor media. Specifically, the confined microenvironment enhanced the accumulation and stabilization of Amadori compounds. This suggested that NADES-based ATPSs hold promise as tailored platforms for controlling the reaction pathways.
尽管天然低共熔溶剂（NADESs）在绿色分离方面的关注度日益提高，但其在双水相体系（ATPS）中的结构稳定性、溶质分配机制以及作为反应介质的潜力等关键方面仍知之甚少。本研究考察了NADES-KHPO双水相体系的开发与应用。合成了四种NADES配方，即甜菜碱-甘油（Bet:Gly）、甜菜碱-丙二醇（Bet:PG）、氯化胆碱-甘油（ChCl:Gly）和氯化胆碱-丙二醇（ChCl:PG），并通过核磁共振氢谱（H NMR）和差示扫描量热法（DSC）对其进行了表征。NADES-KHPO双水相体系的相形成能力受NADES疏水性的影响；具体而言，Bet:PG配方实现相分离所需的KHPO浓度最低（25.1 wt%）。在这些体系中，富含疏水性NADES的相优先分配疏水性氨基酸（如苯丙氨酸，>100；丙氨酸，≈10），而葡萄糖则富集在富含KHPO的相中（≈0.03）。DSC分析证实，NADES在双水相体系中保持了其结构完整性。美拉德反应在37℃的强碱性条件下（上层相pH为11.65，下层相pH为11.34）于Bet:PG-KHPO双水相体系中进行。结果表明，Bet:PG通过氢键作用和受限的分子流动性增强了阿马多里化合物的形成与稳定性。总体而言，本研究表明NADES在双水相体系中保持其超分子结构，使其具备作为选择性萃取剂和微反应器介质的双重功能。具体而言，受限的微环境增强了阿马多里化合物的积累与稳定性。这表明基于NADES的双水相体系有望成为控制反应途径的定制平台。
