Carboxylic acid-based deep eutectic solvents combined with innovative extraction techniques for greener extraction of phenolic compounds from sumac (Rhus coriaria L.)

What if the secret to greener extraction lies in a simple mix of natural acids? A new study shows that carboxylic acid-based NADES can outperform traditional solvents in pulling phenolic compounds from sumac—and do it faster.

Forget harsh solvents. Researchers tested three green carboxylic acid-based natural deep eutectic solvents (NADESs) to extract phenolic compounds from dried sumac leaves. The NADESs were made by pairing choline chloride with lactic acid (ChLa), acetic acid (ChAa), or tartaric acid (ChTa). They compared these against water, methanol, and ethanol using three extraction methods: maceration, homogenate-assisted extraction, and ultrasound-assisted extraction.

The results were striking. ChLa led the pack, yielding total phenolic content up to 23.62 mg GAE/g, while ChAa and water followed closely. In contrast, methanol and ethanol lagged behind. For flavonoids, ChLa again dominated, with ChAa as a strong runner-up. The acidic NADESs simply outperformed conventional solvents.

Speed mattered too. Ultrasound and homogenate-assisted methods achieved similar yields in just 30 minutes, while maceration took 12 hours for comparable results. Principal component analysis confirmed that the choice of solvent and method clearly separated the extracts by their phytochemical profile and antioxidant capacity.

This isn't just a lab curiosity. It's a practical step toward greener, more efficient extraction processes that could reshape how we obtain valuable plant compounds.

Key Points

• ChLa NADES achieves highest TPC up to 23.62 mg GAE/g
• UAE and HAE extract efficiently in 30 minutes
• Acidic NADES outperform water, methanol, ethanol