Hplc grade acetic acid

Gallic acid, chlorogenic acid, (+)-catechin hydrate, vanillic acid, caffeic acid, syringic acid, epicatechin, 4-methylcatechol, coumarin, ferulic acid, resveratrol, quercetin, 3,4-dihydroxybenzoic acid, p-coumaric acid, rutin, sinapic acid, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), Folin–Ciocalteu’s phenol reagent, 2′,7′-dichlorofluorescin diacetate (DCFH-DA), fluorescein disodium salt, 2,2′-azobis (2-amidinopropane) dihydrochloride (ABAP) and quercetin dehydrate were purchased from Sigma-Aldrich (St. Louis, MO, USA). Dulbecco’s Modified Eagle’s Medium (DMEM), dimethyl sulphoxide, HPLC-grade acetic acid and acetonitrile were obtained from Thermo Fisher Scientific (Waltham, MA, USA). Human liver cancer cells (HepG2 cells) were obtained from the American Type Culture Collection (ATCC) (Rockville, MD, USA). Fetal bovine serum (FBS) was obtained from Haoyang Biologicals (Tianjin, China). Deionised water was prepared using a Milli-Q water purification system (Billerica, MA, USA).

Food-grade oat flour was obtained from the Grain Millers, Inc. (Eugene, OR, USA), and food-grade rice flour was obtained from Bob’s Red Mill Natural Foods (Milwaukee, OR, USA). Food-grade fructose and sodium bicarbonate were purchased from Now Foods (Bloomingdale, IL, USA), Church & Dwight Co. (Arm & Hammer^®, Ewing, NJ, USA), respectively. HPLC-grade acetic acid (99.5%), acetonitrile, and methanol as well as phosphate-buffered saline (PBS) tablets were obtained from Fischer Scientific (Pittsburgh, PA, USA). Water (HPLC-grade) was purchased from Macron Fine Chemicals (Center Valley, PA, USA). Commercial OchraTest WB immunoaffinity columns (IAC) were purchased from VICAM (Watertown, MA, USA) for sample cleanup and purification. OTA stock solution (100 mg/L) was prepared in methanol and further diluted with 50% methanol (methanol:water = 50:50; v/v) to prepare working standard solutions. All standard solutions were stored in amber vials at −20 °C.

O. javanica was purchased from Nonghyup mart (Gochang, Jeonbuk, Korea) in June 2021 and dried at 60 °C using the forced convection dry oven (FC 49, Lab House, Seoul, Korea) for 24 h. Dried O. javanica were pulverized using a food grinder (Hanil HMF-3800, Seoul, Korea) and then passed through a 0.42 mm sieve. Powdered O. javanica was stored in polyethylene bag at 4 °C for later use. HPLC grade acetic acid and acetonitrile used for substance analysis of O. javanica were purchased from Thermo Fisher Sci., Inc. (Waltham, MA, USA). Deionized water (≥ 18 Ω) was produced in the laboratory using a Milli-Q purification system (Millipore, Burlington, VT, USA).