Green and highly extraction of phenolic compounds and antioxidant capacity from kinkeliba (Combretum micranthum G. Don) by natural deep eutectic solvents (NADESs) using maceration, ultrasound-assisted extraction and homogenate-assisted extraction

Can a custom-built green liquid unlock the hidden antioxidant power of a celebrated tropical plant better than conventional chemistry? Researchers put natural deep eutectic solvents to the test on dried kinkeliba leaves, and the results rewrite how we extract nature's most valuable compounds.

Kinkeliba (Combretum micranthum) is a tropical plant celebrated for its remarkable phytochemicals and biological activities. To harvest these valuable elements, scientists turned to three carboxylic acid-based natural deep eutectic solvents, pairing choline chloride as a hydrogen bond acceptor with lactic acid, acetic acid, or tartaric acid. These green mixtures were tested against conventional solvents like water, methanol, and ethanol to extract total phenolic compounds, flavonoids, individual phenolics, and antioxidant capacity using DPPH and FRAP assays.

To find the sweet spot for recovery, the study evaluated three distinct extraction methods: conventional maceration extraction, ultrasound-assisted extraction, and homogenate-assisted extraction. The performance varied, but the results point to a clear champion. The lactic acid-based solvent delivered the highest total phenolic and flavonoid content, outperforming traditional solvents like methanol and ethanol.

Speed was another major victory for modern techniques. While traditional maceration required a lengthy 12 hours, ultrasound-assisted and homogenate-assisted extractions achieved fantastic efficiencies in just 30 minutes. Principal component analysis confirmed that combining these acidic solvents with advanced extraction techniques provides the ultimate strategy for maximizing kinkeliba's medicinal potential.

Key Points

• Carboxylic acid-based NADES outperformed traditional solvents like methanol and ethanol.
• Lactic acid combined with choline chloride achieved the highest phenolic yields.
• Ultrasound and homogenate-assisted methods matched 12-hour maceration yields in just 30 minutes.