Epicatechin

Aqueous extracts of various teas (TE), green (GTE), black (BTE) and oolong (OTE) were prepared as described 6. PPA (EC 3.2.1.1 A6255) was purchased from Sigma‐Aldrich Co. Ltd. (St. Louis, US). Pure phenolic compounds including tannic acid (TA), (+)‐catechin (C), (−)‐epicatechin (EC), (−)‐epigallocatechin (EGC), (−)‐epigallocatechingallate (EGCG), (−)‐epicatechingallate (ECG), theaflavin (TF), theaflavin‐3′‐gallate (TF1) and theaflavin‐3, 3′‐digallate (TF2) were obtained from Chengdu Biopurify Phytochemicals Ltd. (Chengdu, China). Other chemicals were of analytical grade.

The polyvinylidene fluoride fiber, MOF-1b, with an inner diameter of 0.5 mm and a pore size of 0.1 μm, was purchased from Tianjin Motianmo Engineering (Tianjin, China). XOD and hypoxanthine were purchased from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). Allopurinol was purchased from Shanghai Macklin Biotechnology Co., Ltd. Tris(hydroxymethyl) aminomethane (Tris) was purchased from Sangon Biotech Co., Ltd. (Shanghai, China). Dopamine was purchased from Aladdin Chemistry Co., Ltd. (Shanghai, China). Epicatechin, Epicatechin gallate, epigallocatechin, epigallocatechin gallate, quercetin, catechin, apigenin and puerarin were all purchased from Chengdu Biopurify Phytochemicals Ltd. (Chengdu, China). HPLC-grade methanol, acetonitrile and formic acid were obtained from Beijing InnoChem Science & Technology (Beijing, China). Water used for all the experiments was purified by a water purification system (ATSelem 1820A, Antesheng Environmental Protection Equipment, Chongqing, China). Unless specified otherwise, all the other chemicals and solvents, such as sodium chloride (NaCl) and hydrochloric acid (HCl), were all of analytical grade and purchased from Chengdu Chron Chemicals Co., Ltd. (Chengdu, China).

Bovine thrombin was obtained from Sigma-Aldrich (Shanghai) Trading Co., Ltd. (Shanghai, China). p-Hydroxybenzoic acid, vanillic acid, naringenin, apigenin, baicalein, catechin, and epicatechin were purchased from Chengdu Biopurify Phytochemicals Ltd. (Chengdu, China). Protocatechuic acid and dihydroquercetin were purchased from Push Bio-Technology Co., Ltd. (Chengdu, China). Gallic acid was the product of Aladdin Reagent Co., Ltd. (Shanghai, China). Tris(hydroxymethyl)aminomethane (Tris) was obtained from Sangon Biotech (Shanghai) Co., Ltd. (Shanghai, China). HCl and acetone were analytical grade reagents and purchased from Chengdu Kelong Chemical Reagent Factory (Chengdu, China).