ABSTRACT
Potential xanthine oxidase (XOD) inhibitors in Lagotis brevituba were captured by using affinity and ultrafiltration. The structures of the captured components were identified by ultra-performance liquid chromatography coupled with Q-TOF mass spectrometry (UPLC-Q-TOF-MS). The binding intensity and binding mechanism between the captured components and XOD were analyzed by using molecular docking software Autodock 4.2. A total of 17 compounds were identified, including 9 flavonoids, 5 phenolic acids and 3 triterpenes. Molecular docking results showed that all the captured components could be spontaneously bound with XOD mainly via hydrogen bond, Van der Waals' force and hydrophobic interaction. From the perspective of binding energy and scoring function, the collected fractions all had potential prospects for XOD inhibitors, and the flavonoid luteolin-3',7 glucuronide had the best effect. The results also showed that affinity and ultrafiltration, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and molecular docking technology can provide a powerful tool for the analysis of XOD inhibitor components in natural products.
ABSTRACT
The chemical constituents of Lagotis brevituba were rapidly determined and analyzed by using ultra performance liquid chromatography tandem quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) method, providing material basis for the clinical application of L. brevituba. The separation was performed on UPLC YMC-Triart C₁₈ (2.1 mm×100 mm, 1.9 μm) column, with acetonitrile-water containing 0.2% formic acid as mobile phase for gradient elution. The flow rate was 0.4 mL•min-1 gradient elution and column temperature was 40 ℃, the injection volume was 2 μL. ESI ion source was used to ensure the data collected in a negative ion mode. The chemical components of L. brevituba were identified through retention time, exact relative molecular mass, cleavage fragments of MS/MS and reported data. The results showed that a total of 22 compounds were identified, including 11 flavones, 6 phenylethanoid glycosides, 1 iridoid glucosides, and 4 organic acid. The UPLC-Q-TOF-MS/MS method could fast identify the chemical components of L. brevituba, providing valuable information about L. brevituba for its clinical application.