RESUMO
A rapid, sensitive and convenient analytical method of ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-QTRAP®/MS2) was proposed for the simultaneous determination of characteristic alkaline and acidic components covering many structure types including alkaloids, phenolic acids, phenylpropanoids and flavonoids in Leonurus japonicus Houtt. (LJ). The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections, limit of quantifications, precision, repeatability, stability and recovery of target components. The developed UPLC-QTRAP®/MS2 was successfully applied to simultaneously determine all target compounds in 38 batches of LJ from 11 different producing regions in China and five organs (including root, caulis, branch, flower and leaf) of LJ from the same stand planting base in Jiangsu Province (China). The result showed that LJ in different regions with different geographical position would affect the accumulation of different compounds, and the significant discrepancies of some target compounds were also observed in different organs of LJ due to different biosynthetic pathway and enzymes in different organs. Furthermore, both hierarchical clustering analysis and principal components analysis were performed to classify the 38 batches of LJ samples from different producing regions on the basis of target compounds. As a result, the samples could be mainly clustered into different groups, which were similar with areas classification. Overall, the presented method would be helpful for the comprehensive utilization and development of LJ resources.