2 2 azino bis 3 ethylbenothiazoline 6 sulphonic acid diammonium salt

The 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), 2,2′-azino-bis(3-ethylbenothiazoline-6-sulphonic acid) diammonium salt (ABTS), 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) and Folin and Ciocalteu’s phenol were produced by Sigma-Aldrich (Saint Louis, MO, USA). The standard chemicals, i.e., gallocatechin (GC), epigallocatechin (EGC), epigallocatechin gallate (EGCG), catechin (C), epicatechin (EC), epicatechin gallate (ECG), catechin gallate (CG), gallocatechin gallate (GCG), gallic acid, chlorogenic acid, ellagic acid, myricetin, quercitrin, kaempferol, astragalin, quercetin, theaflavin and caffeine, were obtained from Derick Biotechnology Co., Ltd. (Chengdu, China). The methanol and formic acid were of chromatography-grade and purchased from Kermel Chemical Factory (Tianjin, China). All the other reagents (such as sodium carbonate anhydrous) were of analytical grade and obtained from Damao Reagent Factory (Tianjin, China).

The 2,2′-azinobis(3-ethylbenothiazoline-6-sulphonic acid) diammonium salt (ABTS), 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), and Folin–Ciocalteu’s phenol reagent were purchased from Sigma-Aldrich (St. Louis, MO, USA). The 18 standard compounds for high-performance liquid chromatography (HPLC) analysis were obtained from Derick Biotechnology Co., Ltd. (Chengdu, China). Tetrahydrofuran, methanol, formic acid, diethyl ether, and ethyl acetate were acquired from Kermel Chemical Factory (Tianjin, China). Acetic acid, sodium acetate, sodium hydroxide, hydrochloric acid, ethylenediaminetetraacetic acid, ascorbic acid, iron(III) chloride hexahydrate, iron(II) sulphate heptahydrate, potassium persulphate, sodium carbonate, ethanol, and n-hexane were bought from Damao Chemical Factory (Tianjin, China). All the reagents were of analytical or HPLC grade, and deionized water was used for all experiments.

The ethanol, acetic acid, chloral hydrate, and sodium chloride were of analytical grade and were obtained from Tianjin Chemical Factory (Tianjin, China). The methanol and formic acid were of HPLC grade and produced by Macklin Chemical Factory (Shanghai, China). Detection kits of SOD, malondialdehyde (MDA), GSH, GPx, and total protein were purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), 6-hydroxy-2,5,7,8-tetramethyl-chromane-2-carboxylic acid (Trolox), 2,2′-azino-bis(3-ethylbenothiazoline-6-sulphonic acid) diammonium salt (ABTS), and Folin–Ciocalteu’s phenol were obtained from Sigma–Aldrich (Saint Louis, MO, USA). The standard chemicals for HPLC analysis were produced by Derick Biotechnology Co., Ltd. (Chengdu, China), including gallocatechin (GC), epigallocatechin (EGC), catechins (C), EGCG, epicatechin (EC), gallocatechin gallate (GCG), epicatechin gallate (ECG), and catechin gallate (CG), gallic acid, chlorogenic acid, caffeine, ellagic acid, myricetin, quercitrin, astragalin, quercetin, theaflavin, and kaempferol. All other chemicals or reagents were of analytical grade, and deionized water was used for all experiments.