Study on the potential chemical markers for the discrimination between raw and processed Schisandrae Chinensis Fructus using UPLC-Q-TOF/MS coupled with multivariate statistical analyses

In traditional Chinese medicine, both crude and processed herbs are used to treat different diseases. Therefore, suitable chemical markers are crucial for the discrimination between these crude and processed herbs. In this study, a rapid strategy which used ultra-high performance liquid chromatography combined with a triple quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was coupled with multivariate statistical analyses to rapidly explore the potential chemical components as chemical markers. These proposed potential chemical markers were then validated. Schisandrae Chinensis Fructus (SCF) was selected as the research object, and batches of both crude and vinegar processed samples were determined using UPLC-Q-TOF/MS. The datasets of the t(R)-m/z pairs, ion intensities, and sample codes were subjected to a principal component analysis (PCA), as well as an orthogonal partial least squared discriminant analysis (OPLS-DA), in order to holistically compare the differences between the crude and processed samples. The identities of the potential markers were arrived at by comparing the mass spectra and retention times with those of the reference compounds, and/or were tentatively assigned by matching an empirical molecular formula with that of the published compounds. Using this proposed strategy, the Schisantherin D, Schisandrin A and Schisandrin B and 5-Hydroxymethylfurfural were rapidly determined to be the most characteristic chemical markers of the SCF and vinegar-processed SCF (VSCF), respectively. This newly proposed strategy can not only be potentially used to explore chemical markers, but also used to investigate the chemical transforming mechanisms underlying traditional herb processing.