Figure 2: (a) Four herbs Ku-Shen (Sophora flavescens), Qing-Feng-Teng (Sinomenium acutum), Huang-Bai (Cortex Phellodendri Chinensis), and Bi-Xie (Dioscorea tokoro Makino) in QLY. (b) and (c) Principal component analysis of the target profiles for each herbal ingredient in QLY. Each dot represents one herbal ingredient plotted against its target profile. Ingredients are color coded according to the four herbs (b) and the three types of the chemicals (c) in QLY. Samples were distributed by their similarity in target profiles using dimensionality reduction. The different chemical types cluster in terms of target profiles can be separated from each other. The four herb clusters in terms of target profiles are partially intermix with each other.