Nitrotetrazolium blue chloride nbt

Flavone, 6-hydroxy flavone, 3-hydroxy flavone, 7-hydroxy flavone, 6-methoxy-flavone, 6-methoxy flavanone, naringenin and naringin were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). Biochanin A, genistein, apigenin, puerarin, wogonin, catechin (C), epicatechin (EC), luteolin, daidzein, daidzin, resveratrol, piceid and neohesperidin-dihydrochalcone were purchased from Aladin Co. Ltd. (Shanghai, China). Galangin, kaempferol, quercetin, myricetin, baicalein and chrysin were purchased from Wako Pure Chemical Industries (Osaka, Japan). All other polyphenols were obtained commercially from Shanghai Tauto Biotech CO., Ltd. (Shanghai, China). Peptone, yeast extract, agar, 1-deoxy-1-morpholino fructose (DMF) and bovine serum albumin (BSA) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Nitrotetrazolium Blue chloride (NBT) was obtained from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). Kanamycin and carbenicillin were purchased from Shanghai Xinya Pharmaceutical Co., Ltd. (Shanghai, China). Fetal bovine serum (BP) of no phage and low endotoxin was from Sijiqing Biological Engineering Materials Co., Ltd. (Hangzhou, China). All other reagents and solvents were analytical grade and used without further purification.

XO from bovine milk (Grade I, 10.87 units mL⁻¹) and xanthine (purity ≥ 98%) were supplied by Solarbio Co. (Beijing, China), and their stock solutions with concentrations of 5.00 μM and 0.50 mM were prepared using Tris–HCl buffer (pH 7.4, 0.05 M). ECG (purity ≥ 98%) was purchased from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China) and dissolved in ethanol−water (40%, v/v) to prepare the stock solution (5.00 mM). Allopurinol and 2,2-diphenyl-1-picrylhydrazyl (DPPH) from Sigma–Aldrich Chemical. (St. Louis, MO, USA) used dimethyl sulfoxide (DMSO) and absolute ethanol as solvents, respectively. Phenazine methosulfate (PMS), nitrotetrazolium blue chloride (NBT), and triton X−100 were all provided by Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China), while β-NADH (NADH) was obtained from Aladdin Reagent Co. (Shanghai, China), and they were all soluble in ethanol. The proportions of ethanol and DMSO were strictly controlled in all experiments to ensure that they did not influence the results [30 (link)]. All other chemical reagents were of analytical purity, and the water used throughout the experiments was ultrapure water.