Catechin

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.

Triphala oral liquids were manufactured by Sichuan Huamei Pharmaceutical Co., Ltd., and the batch number was 1601001. Water was purified using a Milli Q water purification system (Millipore, Bedford, MA, USA). HPLC-grade methanol was purchased from Fisher Chemical (Pittsburg, PA, USA). HPLC-grade formic acid was obtained from Chengdu Kelong Chemical Factory (Chengdu, China). Anhydrous ethanol (analytical purity) was also bought from Chengdu KeLong Chemical Factory (Chengdu, China). Standard of 1,1-diphenyl-2-picrylhydrazyl (DPPH BR 97%R1701) was purchased from Duly Biotech Co., Ltd. (Nanjing, China). Standards of gallic acid (GA, no.4051109), epigallocatechin (EGC, no.14051611), epicatechin gallate (ECG, no.14050602), corilagin (CR, no.PRF7102406), gallocatechin (GC, no.4051109), catechin (C, no.14051508), epigallocatechin gallate (EGCG, no.14121608), gallocatechin gallate (GCG, no.14102009), ellagic acid (EA, no.PRF7101305), chebulagic acid (CLA, no.CHB171222), and chebulic acid (CA, no.AP8070902) were purchased from Chengdu Biopurify Phytochemicals Ltd. (Chengdu, China). The purity of the 12 standards was each above 98.0%. Magnesium standard solution (no. GSB04-1735-2004), calcium standard solution (no. GSB-SCD-002-2013), and iron standard solution (no. GSB04-1742-2004) were all received from National Non-ferrous Metals and Electronic Materials Analysis and Testing Center.

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).