Ginsenoside rg1

The chemical constitutions of PNS and PNE were quantitatively determined using a Waters ACQUITY-UPLC CLASS system (Waters Corp., USA) coupled with an ACQUITY UPLC BEH phenyl column (150 mm × 2.1 mm, 1.7 μm) maintained at 45°C. Elution was performed with a mobile phase of water (A) and Acetonitrile (B) under a gradient program: 0-10 min, 19% B; 10-15 min, 19-35% B; 15-20 min, 35-38% B. The flow rate was 0.4 mL/min, and the injection volume was 2 μL. The analytes were monitored at the UV wavelength of 205 nm. Prior to the next injection, the column was washed with 100% B for 2 min and then equilibrated with the initial mobile phase for 3 min. Notogisenoside R1, ginsenoside Rb1, ginsenoside Re, ginsenoside Rg1, and ginsenoside Rd (the purities of all standards were higher than 98% by HPLC analysis) were purchased from Chengdu Pufei De Biotech Co., Ltd. (China). Acetonitrile was purchased from RCI Labscan Limited (Thailand) of HPLC grade. Milli-Q water was prepared using a Milli-Q system (Millipore, USA).