*4.6. Sample Preparation for UPLC-ESI-MS*/*MS Analysis*

A solution of each extract (MeOH/H2O 8:2 *<sup>v</sup>*/*<sup>v</sup>*, 1 mg/mL) was submitted to the solid-phase extraction using RP18 cartridge, eluted with MeOH/H2O 8:2 (*v*/*v*). After drying, 1 mg was dissolved in 1 mL of MeOH/H2O 8:2 (*v*/*v*) solution (solution A) and an aliquot was diluted with MeOH/H2O 8:2 (*v*/*v*) to reach a final volume of 1 mL (150 μg/mL), and was filtered through a 0.22 μm nylon filter membrane. The final solution was used for quantification analysis. For PCA, the solution A was diluted with MeOH/H2O 8:2 (*v*/*v*) to reach a final concentration of 1 μg/mL. The sample preparations were triplicated.
