Figure 2

Online DPPH assay. Representative chromatograms of A. paniculata extract #9. The chromatogram at 227 nm (black line) is contrasted with the DPPH absorbance at 529 nm (red line). Compounds that have DPPH antioxidant activity are observed as a negative peak at 529 nm. Numbered peaks were identified as chlorogenic acid (#1), andrographolide (#12), andropanoside (#13), neoandrogrpapholide (#19), deoxyandrographolide (#23), and 14-deoxy-11,12-didehydroandrographolide (#24).