Ultrasound-Assisted Extraction, Macroporous Resin Purification, and Antioxidant Activity of Chlorogenic Acid from Eucommia ulmoides Leaves

TL;DR

This study optimizes the extraction and purification of chlorogenic acid from Eucommia ulmoides leaves, showing it has strong antioxidant properties suitable for food applications.

Contribution

The study introduces an optimized ultrasound-assisted extraction and resin purification method for chlorogenic acid from Eucommia ulmoides leaves.

Findings

Optimized extraction parameters achieved a 6.96% yield of chlorogenic acid using 70% ethanol.

Purification with NKA-II resin increased CGA purity to 82.72%.

The compound showed strong antioxidant activity, scavenging over 96% of DPPH and ABTS radicals at 5 mg/mL.

Abstract

Chlorogenic acid from Eucommia ulmoides leaves is a promising natural antioxidant for food applications, yet its extraction and purification require optimization to improve yield and purity. This study employed ultrasound-assisted ethanol extraction on fresh leaves, evaluating the effects of ethanol concentration, solid-to-liquid ratio, extraction time, and temperature on CGA yield. Optimal extraction parameters were determined using response surface methodology. Purification with NKA-II macroporous resin increased CGA purity to 82.72%. SEM analysis revealed wrinkled and porous surface structures, while FTIR confirmed the presence of characteristic hydroxyl, carbonyl, and aromatic groups. Under optimized conditions (70% ethanol, solid-to-liquid ratio 1:20 g/mL, 58 °C, 61 min), the extraction yield reached 6.96%. In vitro assays demonstrated strong antioxidant activity, with scavenging rates of 96.01% for DPPH, 89.69% for hydroxyl, and 99.82% for ABTS radicals at 5 mg/mL. These findings provide an efficient method for obtaining chlorogenic acid from Eucommia ulmoides leaves and support its potential as a functional food ingredient.

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