Ultrasonic-Assisted extraction of luteolin from peanut shells using supramolecular solvents and its molecular mechanism

This study innovatively employs ultrasound-assisted extraction (UAE) in conjunction with supramolecular solvents (SUPRAS) for the extraction of luteolin from peanut shells, while also investigating the potential mechanism underlying this extraction process. Initially, the formation mechanism of SUPRAS was characterized using Fourier-transform infrared spectroscopy (FTIR). Based on the results of single-factor experiments, the extraction process was optimized using response surface methodology (RSM), resulting in the determination of optimal conditions: an ultrasound temperature of 67 °C, a SUPRAS/equilibrium solution (EqS) volume ratio of 5:1, and a solid-to-liquid ratio of 1:36 g/mL. Under these conditions, the maximum luteolin yield reached 1.645 mg/g. Furthermore, through independent gradient model (IGMH) calculations, molecular orbital theory, interaction energy analysis, and molecular dynamics simulations, it was revealed that the predominant interaction force between the supramolecular solvent and the target compound is hydrogen bonding. Notably, this study also compares the SUPRAS-UAE extraction method with the traditional extraction in terms of efficiency, economic costs, and environmental impact. The results indicate that the SUPRAS-UAE technique demonstrates significant advantages in terms of its green and high-efficiency characteristics. It provides a new sustainable strategy for the efficient recovery of natural active ingredients in chemical engineering and related fields.