Recent Advances in the Use of Natural Deep Eutectic Solvents for Natural Product Sample Preparation: Focus on Purification, Characterization, and Sustainability.

This review examines recent advances in the use of natural deep eutectic solvents (NaDES) for natural product sample preparation, with emphasis on extraction, purification, analytical compatibility, and sustainability. NaDES emerge as versatile, tunable, and biocompatible media that enhance the recovery and stability of diverse phytochemicals through extensive hydrogen‑bond networks and customizable polarity. The review summarizes current knowledge on NaDES formation principles, key physicochemical properties, and classification and evaluates their performance across conventional and advanced extraction techniques, including ultrasound, microwave, and pressure‑assisted processes. Evidence shows that NaDES frequently outperform traditional organic solvents in selectivity, extraction efficiency, and compound preservation. Their integration into purification workflows, chromatographic and spectroscopic analysis, and sensor platforms highlights growing analytical relevance. Sector‑specific applications in food, cosmetics, and pharmaceuticals illustrate the potential for direct formulation, improved bioactivity, and enhanced functional properties. Sustainability assessments using green metrics demonstrate that NaDES‑based methods reduce solvent consumption, waste generation, and environmental impact. Remaining challenges include viscosity management, removal strategies, and regulatory acceptance. Overall, NaDES represent a transformative class of green solvents that advances natural product research by combining efficiency, analytical compatibility, and strong alignment with green chemistry principles.