Functional food research is hindered by the complex natural food matrices, which demand accurate, rapid methods for identifying bioactive compounds. Here, we developed an activity-guided online HPLC-pancreatic lipase recognition system to simultaneously recognize and monitor active chromatographic peaks in Rubus irritans fruit extracts. Four compounds, namely cinnamic acid (1), 5-hydroxy-6,7,3',4'-tetramethoxyflavone (2), 1-hydroxy-2,3,5-trimethoxyxanthone (3), and salvigenin (4), were first isolated from these fruits via medium- and high-pressure liquid chromatography. In vitro assays showed that all inhibited pancreatic lipase, with IC₅₀ values of 444.90 ± 0.19, 142.64 ± 0.93, 168.70 ± 0.64, and 118.84 ± 0.89 μM, respectively. Salvigenin (4) acted via reversible competitive inhibition. Molecular docking revealed the binding modes of the four compounds in the pancreatic lipase active site, with salvigenin exhibiting the lowest binding energy (-7.3 kcal/mol), followed by compounds 1–3 (-5.4, -6.8, and -6.9 kcal/mol). DFT calculations indicated that salvigenin had a smaller HOMO-LUMO gap and a higher dipole moment, suggesting favorable reactivity. Overall, our study's primary contribution is the establishment of an efficient activity-guided online recognition system for precisely recognizing and isolating natural pancreatic lipase inhibitors from edible fruits, with R. irritans fruits and their derived salvigenin identified as promising functional food ingredients. • An online HPLC-pancreatic lipase recognition system was developed. • The system enables precise recognition of pancreatic lipase inhibitors. • Salvigenin exhibited reversible and competitive inhibition of pancreatic lipase. • The results confirm the online system's effectiveness in precisely recognizing pancreatic lipase inhibitors.
Bao et al. (Tue,) studied this question.