157527.fig.001
Figure 1: The HPLC chromatogram of chlorogenic acid (1) in the root of I. helenium (Column, Hypersil column ( ); mobile phase, acetonitrile: 0.1% phosphoric acid (10 : 90); flow rate, 1 mL/min; column temperature, 30°C; wavelength, 327 nm; injection volume, 20  L).