*3.1. Chemicals*

Organic solvents (HPLC grade) were purchased from Merck KGaA (Darmstadt, Germany). Folin–Ciocalteu reagent was purchased from Wako Pure Chemicals (Osaka, Japan). The standard compounds of panasenoside and kaempferol were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Pure ginsenoside standards (98%) were purchased from ChromaDex (Santa Ana, CA, USA) and Ambo Institute (Daejeon, Korea).
