An integrated amino acid ionic liquid mediated microwave-assisted extraction for simultaneously obtaining essential oils, forsythoside A, forsythin and polysaccharides from Forsythia suspensa fruits

This study developed an integrated amino acid ionic liquid-mediated microwave-assisted extraction (AAIL-MAE) method for the concurrent recovery of essential oils (EOs), forsythoside A, forsythin, and crude polysaccharides from Forsythia suspensa fruits. Eight amino acid ionic liquids were screened, and [His][HSO 4 ] was selected as the extraction medium. Extraction conditions were optimized using single-factor experiments and response surface methodology. The optimized conditions were 0.23% [His][HSO 4 ], a liquid–solid ratio of 16 mL/g, microwave power of 540 W, and an extraction time of 34 min. Under these conditions, the respective yields were 9.31 ± 0.35, 63.45 ± 2.74, 5.95 ± 0.26, and 62.58 ± 2.21 mg/g. Compared with conventional microwave-assisted extraction and hydrodistillation, AAIL-MAE significantly increased the yields of forsythoside A and forsythin while maintaining comparable yields of EOs and crude polysaccharides. Kinetic analysis showed a rapid initial extraction stage followed by a gradual approach to equilibrium, and the second-order model provided a slightly better fit. GC–MS analysis identified 34 EO constituents, with α -pinene, β -phellandrene, β -pinene, and terpinen-4-ol as the predominant compounds. These results demonstrate the feasibility of the proposed process as an integrated strategy for recovering multiple bioactive fractions from F. suspensa fruits.