Figure 2.

Representative chromatograms of methanol extract (PLASEM) of P. officinalis. (A) UPLC-Q-TOF chromatogram; (B) HPLC-UV-DPPH^•-scavenging chromatogram showing 19 active compounds (negative peaks at 515 nm), which were detected by comparing their retention times with the UV chromatogram recorded at 280 nm: gallic acid derivatives (3, 4, 5, 6, 7, 10, 12, 14, 15, 16, 17, 19, 20, 21), quercetin derivatives (11, 13), paeoniflorin derivatives (9, 18), and unknown compounds (22, 23).