Quantitative Ginsenoside Analysis in Ginseng

The standard ginsenosides, namely, Rg1, Re, Rb1, Rb2, Rc, and Rd, were purchased from Shanghai Tauto Biotech Company (Shanghai, China). The standard solutions were dissolved in methanol (Fair Lawn, NJ, USA) for further experiments. Ten samples of P. ginseng roots (4-year-old) from each plot were pooled and considered one sample. P. ginseng extract preparation was performed according to the description of Dong et al. [22 (link)]. Ginsenoside contents were determined through high-performance liquid chromatography (Agilent 1260, USA) using a system equipped with a binary pump, an online degasser, a column compartment, and an auto plate sampler. The reA C18 reversed phase column (250 mm × 4.6 mm, i.d. 5 µm; Eclipse XDB, Agilent, USA) was used for separation. The column temperature was kept at 25 °C, and the flow rate and wavelength were 1.0 ml min⁻¹ and 203 nm, respectively. The gradient was composed of water and acetonitrile. The linear gradient was set as follows: 0–12 min for 19% acetonitrile and 12–60 min for 19–40% acetonitrile.