Ammonium hydroxide

Ginsenoside Re (≥ 98.0% purity) was purchased from School of Chemistry, Jilin University (Changchun, China). Digoxin [internal standard (IS)] with purity of 98.0% or more was purchased from Pure Chemical Standard Co., Ltd. (Chengdu, China). Vitamin B₁ (≥ 99%), vitamin B₂ (≥ 98%), vitamin B₃ (≥ 99%), vitamin B₅ (≥ 99%), vitamin B₆ (≥ 99%), vitamin B₇ (≥ 97%), vitamin B₉ (≥ 97%), and vitamin B₁₂ (≥ 98%) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Liver glycogen assay kits, urea assay kits, and lactic acid (LA) assay kits were purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). Ammonium hydroxide (HPLC grade) was purchased from Beijing Chemical Works (Beijing, China).
Solid-phase extraction (SPE) columns (Oasis HLB 3 cm³/60 mg) were purchased from Waters (Milford, MA, USA). Methanol and acetonitrile (both HPLC grade) were purchased from Fisher Scientific (NJ, USA). Milli-Q (Millipore) water was used in all experiments. All other chemicals were of HPLC or analytical grade.

All the reagents were commercially available products and used directly without further purification. Deionized water was used directly in all experiments. Propidium iodide (PI) and fluorescein diacetate (FDA) were purchased from Invitrogen. 1-Aminopyrrole (Py-NH₂, >98.0%) was purchased from Tokyo Chemical Industry. Ferric trichloridehexahydrate (FeCl₃·6H₂O), copper chloride dehydrate (CuCl₂·2H₂O), 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazoliumbromide (MTT), mercaptoethylamine (MA, 99+%), mercaptoglycerol, 3-mercaptopropionic acid (MPA, 99+%) and glutathione (GSH, 99%) were got in Sigma-Aldrich. Ammonium hydroxide (NH₃·H₂O, 25%) was purchased from Beijing Chemical Works.