Recovery of Natural Products from Deep Eutectic Solvents by Mimicking Denaturation

A strategy was developed to recover natural products from deep eutectic solvents based on denaturation of the solvents. A method similar to nucleic acid denaturation was used to disrupt the intermolecular forces in the deep eutectic solvents to reduce their ability to solubilize and interact with the flavonoids at recovery. MIL-100 (Cr) was added to the system for sorptive separation and recovery of the target compounds from the denaturized deep eutectic solvents. The factors affecting denaturation of the deep eutectic solvents and adsorption of the target compounds were systematically investigated and optimized. The recovery method was further combined with mechanochemical extraction to establish a convenient and efficient protocol for obtaining natural products from plants. Moreover, due to the conjugated structure of MIL-100 (Cr), the adsorbed natural products could be directly analyzed by atmosphere matrix assisted laser desorption ionization-mass spectrometry (AP/MALDI-MS) without elution. This study provided a strategy for improving the efficiency of separation and recovery of natural products using deep eutectic solvents and also established a protocol for obtaining or analyzing natural products in a green, efficient, and convenient manner.