Towards a Green and Sustainable Valorization of Salix amplexicaulis: Integrating Natural Deep Eutectic Solvents and Microwave-Assisted Extraction for Enhanced Recovery of Phenolic Compounds

What if the key to unlocking nature's pharmacy lies in a solvent made from sugar and lactic acid? A new study shows how a green cocktail can outperform traditional methods in extracting healing compounds from an overlooked willow species.

Forget toxic solvents and energy-hungry processes. Scientists are turning to natural deep eutectic solvents (NADES)—eco-friendly mixtures that act like molecular magnets for bioactive compounds. In a fresh study, researchers paired NADES with microwave-assisted extraction (MAE) to tap into the hidden potential of Salix amplexicaulis, a shrub whose leaves and bark have been largely ignored by modern medicine.

The team synthesized four NADES combinations, including lactic acid–glucose and glycerol–urea, and tested them against conventional methods like ethanol maceration. The standout? A lactic acid–glucose (5:1) mixture, which pulled out the highest number and amount of phenolic compounds from both bark and leaves. Using HPLC-DAD, they identified seven phenolic acids and four flavonoids—compounds known for their antioxidant and anti-inflammatory properties.

This isn't just a lab curiosity. MAE-NADES proved fast, cost-effective, and environmentally friendly, offering a sustainable route to valorize this plant for pharmaceutical use. The study underscores NADES as a promising alternative to water and toxic organic solvents, aligning perfectly with green chemistry principles. The future of plant extraction might just be a little sweeter—and a lot greener.

Key Points

• NADES with lactic acid–glucose (5:1) extracted the most phenolics.
• MAE-NADES is fast, cost-effective, and eco-friendly.
• Seven phenolic acids and four flavonoids identified in willow extracts.