Deep eutectic solvent extraction of chlorogenic acid from dandelion with ultrasonic-assisted: Process optimization, purification, and bioactivity

Dandelion, a widely distributed medicinal plant, is rich in chlorogenic acid (CGA). However, research on the extraction and purification of CGA from dandelion, as well as its bioactivity, is insufficient. Therefore, this study developed an efficient and economic method for extracting CGA from dandelions using ultrasonic-assisted deep eutectic solvents. The DES system comprised betaine and oxalic acid, demonstrated high extraction efficiency, and was identified as the optimal extraction solvent. Furthermore, Response Surface Methodology (RSM) was employed to optimize the extraction conditions, which included: water content of 42 %, ultrasonic power of 300 W, ultrasonic temperature of 70 °C, ultrasonic time of 32 min, and solid-liquid ratio of 1:30 g/mL. Under these conditions, the extraction yield of CGA reached 4.27 mg/g. Dandelion samples treated with ultrasound-assisted DES had improved extraction efficiency. Following further purification with macroporous resin, the purified extract of CGA (PECGA) demonstrated significant antioxidant activity. Moreover, this ultrasonic-assisted PECGA showed considerable antibacterial efficacy against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). This study provides evidence for potential applications of CGA extracted from dandelions as a natural antioxidant and antibacterial agent in the food and pharmaceutical industries.