Enhanced Eugenol Composition in Clove Essential Oil by Deep Eutectic Solvent-Based Ultrasonic Extraction and Microwave-Assisted Hydrodistillation

Imagine boosting the key medicinal compound in clove oil by nearly 10%—without harsh chemicals. That's exactly what deep eutectic solvents and a little ultrasonic magic just achieved.

Clove oil is a treasure chest of bioactive compounds, with eugenol leading the charge. This molecule, prized in medicine and food, just got a green extraction upgrade. Researchers swapped traditional solvents for deep eutectic solvents (DESs)—eco-friendly alternatives that are turning heads in extraction science. They paired these solvents with two techniques: microwave-assisted hydrodistillation (MHD) and an ultrasonic pretreatment before MHD.

The results were striking. Using choline chloride and oxalic acid in a 1:2 molar ratio, the team pushed eugenol purity to 82.90% and 83.34%—up from 75.48% without DESs. That's a boost of 7.42% and 8.36%, respectively. But the benefits didn't stop at composition. The enhanced oils also flexed stronger antioxidant muscles, with DPPH radical scavenging activity at IC50 levels of 2.16 and 2.19 µg/mL, significantly better than DES-free extracts.

This isn't just a lab curiosity. The process is straightforward, environmentally friendly, and scalable. The authors suggest it could be a game-changer for extracting other edible essential oils, opening doors for food and pharmaceutical industries. So, the next time you smell clove, know that science just made it even more powerful—and greener.

Key Points

• DES-based extraction boosted eugenol purity by 7.42–8.36%.
• ChCl-OA solvent achieved 82.90% and 83.34% eugenol.
• Enhanced oils showed stronger antioxidant activity (IC50 ~2.16 µg/mL).