Folin ciocalteu phenol reagent

The W. somnifera extract (aqueous extract, 20:1) was purchased from Sanyuan Longsheng Biotechnology Co.(China). Peptone, beef extract and yeast extract were obtained from Aoboxing Biotechnology Co., China. Glucose, monopotassium phosphate, Na-acetate, magnesium sulfate, ethanol, sodium nitrite, aluminum nitrate, ethyl acetate, and sodium hydroxide were purchased from Kermel Scientific Co. (China). Folin–Ciocalteu phenol reagent was obtained from Solarbio. In addition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,6-Di-tert-butyl-4-methylphenol (BHT) were purchased from Sigma-Aldrich Inc. (Germany). Pyrogallic acid, 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, ascorbic acid and rutin were obtained from Aladin Industries Inc. (China).

Acetonitrile and methanol were purchased from Thermo Fisher Scientific (Waltham, MA, USA), and formic acid was purchased from DiKMA Technologies (Beijing, China). Water was generated by a Milli-Q Integral water purification system (Millipore Billerica, Billerica, MA, USA). Folin–Ciocalteu phenol reagent was purchased from Solarbio Life Sciences (Beijing, China). The antioxidant capacity assay kit with a Rapid ABTS method was purchased from Beyotime Biotechnology (Shanghai, China). The antioxidant capacity assay kit by DPPH assay was purchased from Dojindo Beijing Co., Ltd. (Beijing, China). The standards of vitamin C, p-coumaric acid, caffeic acid, trans-ferulic acid, kaempferol, and quercetin were purchased from Alta Scientific Co., Ltd. (Tianjin, China).