Green and efficient ultrasound-assisted supramolecular solvent extraction of Plantago asiatica L.: Process optimization, mechanism, and hypouricemic efficacy

Plantago asiatica L. (PA), a traditional Chinese medicinal and edible plant, is rich in the hypouricemic bioactive components plantamajoside (PMS) and acteoside (ACT). This study pioneers the development of an efficient and environmentally friendly ultrasonic-assisted supramolecular solvent extraction (SUPRAS-UAE) method for the extraction of PMS and ACT. Additionally, it elucidates the sonochemical mechanisms underlying SUPRAS-UAE and conducts a comparative analysis of its extraction efficiency against conventional methods. The ultrasonic apparatus utilized was an SB25-12DTD power-adjustable heated cleaner operating at 40 kHz. The SUPRAS solvent system comprised 9% (v/v) decanoic acid, 38% (v/v) ethanol, and 53% (v/v) water, with a pH of 6. Through optimization using single-factor experiments and response surface methodology, the optimal extraction conditions were determined to be an ultrasonic power of 840 W, an ultrasonic duration of 50 min, an ultrasonic temperature of 53℃, and a liquid-solid ratio of 82 mL/g. Mechanistically, the application of ultrasound facilitated the dynamic reorganization of SUPRAS micelles and the mechanical disruption of PA cell walls, thereby synergistically enhancing the release of the target components. Compared to conventional extraction methods, SUPRAS-UAE demonstrated superior extraction efficiency, environmental sustainability, and solvent recyclability.