FIGURE 3.

PCA of all Danshen samples. The PCA-X corresponds to the binned regions of all ¹H-NMR spectra of Danshen samples as X variables. All X variables are scaled by Pareto scaling. In (A) PCA scatter score plot and (B) Hierarchical Clustering Analysis for PCA, Figure (C) and (D) are the loading plots of figure (A). The colours of the loading plots are referring the p value of the X variable contribute to the principal component 1 in figure (C), and the component 2 in figure (D). A, authenticated samples; C, Chinese online store samples; V, Vietnamese samples