High-performance liquid chromatography and liquid chromatography-mass spectrometry analysis
The ginsenoside composition of the GS sample was analyzed by high-performance liquid chromatography (HPLC; Agilent Technologies, Billerica, MA, USA) with a diode-array detector (Ultimate3000, DIONEX, Sunnyvale, CA, USA) using the Elite Kromasil C18 column (4.6×250 mm, 5 µm). The mobile phase condition was ultrapure water (solvent A) and acetonitrile (solvent B; Sigma-Aldrich), and the column temperature was set at 35°C. The flow rate was 1.0 mL/min, and the chromatograms were obtained using a UV/VIS detector at 203 nm. According to the retention time and chromatographic peak area of ginsenoside standards, 18 ginsenosides were identified and quantified as Rg1 (11.23%), Re (18.32%), Rf (4.37%), Rb1 (5.96%), Rc (10.34%), Rh1 (1.40%), Rb2 (3.15%), Rb3 (0.57%), F1 (0.22%), Rd (7.42%), F3 (2.83%), Rk3 (6.30%), S-Rg3 (2.46%), R-Rg3 (1.00%), PPT (0.16%), Rk1 (1.72%), Rg5 (2.31%), and Rh2 (1.68%) in the GS sample(Supplementary Fig. 1A and 1B) . Based on mobile phase and elution gradient from HPLC, LC-mass spectrometry (LC-MS) was performed on the Thermo LTQ XL system (Thermo Fisher Scientific, Carlsbad, CA, USA) with the Agilent ZORBAX SB-C18 column (2.1×100 mm, 1.7 µm) to obtain the chromatogram of different ginsenosides in the negative ion mode. MS analysis conditions were set as follows: gas temperature 270 °C, electric voltage 3.5 kV and scan range from 165 to 2000 m/z. The MS chromatogram and properties of different ginsenosides from GS are shown in Supplementary Fig. 2A and 2B .