Fig. 3

PCA and OPLS-DA scores obtained from the DL data. a PCA and b OPLS-DA score plots of the DL data obtained from processed Rehmanniae radix samples, showing two separated clusters. The separated clusters were marked with a “△” (cluster 1) or a “+” (cluster 2) symbol, in which cycles 1–3 belongs to one cluster and cycles 4–9 belongs to another cluster