protocatechuic acid

Aucubin, geniposidic acid, protocatechuic acid, chlorogenic acid, caffeic acid, geniposide, pinoresinol diglucoside, genipin, ferulic acid, liriodendrin, rutin, syringaresinol, quercetin, kaempferol from Weikeqi Biological Technology Co., Ltd. (Chengdu, China). All standards were identified with the purity higher than 98%. Methanol and formic acid of UPLC-MS grade were supplied by Fisher Scientific (Geel, Belglum).

The standards of eleutheroside E, protocatechuic acid, isofraxidin, chlorogenic acid and eleutheroside B were obtained from Sichuan Weikeqi-Biotech Co., Ltd., and their purities were all ≥ 98%. Millipore Milli-Q Water Purification system was utilized to produce deionized water (at a resistance of 18.25 MX) for HPLC. The absolute ethyl alcohol was provided by Tianli Chemical Reagent Co.,Ltd.

Folin-Ciocalteureagent,gallic acid, catechinand otherpolyphenolicstandardswere purchasedfrom SichuanWeikeqiBiologicalTechnologyCo., Ltd. (China).1,1-Diphenyl-2-picrylhydrazyl(DPPH),2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonicacid)diammoniumsalt(ABTS),2,4,6-tris(2-pyridyl)-s-triazine(TPTZ),trolox,α-amylase,α-glucosidaseand 4-nitrophenyl-α-D-gluco-pyranoside(α-PNPG)wereobtainedfromSigma–Aldrich(USA).

The standards of isofraxidin, eleutheroside E,

eleutheroside B, protocatechuic acid, chlorogenic acid, and ursolic

acid were all obtained from Sichuan Weikeqi-Biotech Co., Ltd.

(Chengdu, China), and the purity was ≥98%. Macroporous resins

such as NKA-9, D101, HPD-400, ADS-17, and AB-8 were obtained

by Nankai Hecheng S&T (Tianjin, China).

enzyme-linked immunosorbent assay (ELISA) kit was obtained from Multi Science Biotechnology Co., Ltd. (Hangzhou, China). Reference standards of astragaloside, heterophyllin B, atractylodin, harpagide, berberine, baicalin, puerarin, quercetin, protocatechuic acid and tanshinone II A were obtained from Sichuan Weikeqi Biological Technology Co., Ltd. (Sichuan, China).

Luteolin-7-O-β-D-glucoside (CAS 68321-11-9, 98%), protocatechuic acid (CAS 99-50-3, 98%), catechin (CAS 154-23-4, 98%), epicatechin (CAS 18829-70-4, 98%), naringenin (CAS 480-41-1, 98%), isoquercitrin (CAS 482-35-9, 98%), and phlorizin (CAS 60-81-1, 98%) were purchased from Weikeqi Biological Technology Co., Ltd. (Chengdu, China). Gallic acid (CAS 149-91-7, 98%) was purchased from Shanghai Aladdin Chemistry Co., Ltd. (Shanghai, China)

Quercetin (QE), gallic acid (GA), Folin-Ciocalteu reagent, 2,2′-azobis-amidinopropane (ABAP), and dichlorofluorescin diacetate (DCFH-DA) were purchased from Sigma-Aldrich Inc. (St. Louis, USA). Protocatechuic acid (PA), ferulic acid (FA), epicathin (Epi), catechin (CE), QE glycosides, isorhamnetin (IS) glycosides and kaempferol (KA) glycosides were purchased from Weikeqi Biological (Chengdu, China). Human liver cancer cells HepG2 were purchased from American Type Culture Collection (ATCC, Manassas, VA, USA).

Reference compounds, comprising specnuezhenide, oleuropein, nuezhenidic acid, ligustroflavone, G13, oleoside 11-methyl ester, tyrosol, hydroxytyrosol, salidroside, acteoside, protocatechuic acid, galuteolin, apigenin, quercitrin, rutin, luteolin, quercetin, oleanolic acid, ursolic acid, betulin, emodinmonomethyl ether, 3β-O-acetylpomolic acid, oleonuezhenide, 6′-O-trans-cinnamoyl-8-epikingisidic acid, ligulucidumoside A, ligulucidumoside C, oleuropeinic acid, echinacoside, 3β-O-acetylpomolic acid, oleonuezhenide, 6′-O-trans-cinnamoyl-8-epikingisidic acid, ligulucidumoside A, ligulucidumoside C and geniposide (purity ≥98%), were provided by Yifang S&T Co. Ltd (Tianjin, China), the National Institutes for Food and Drug Control and Sichuan Weikeqi Pharmaceutical Technology Co. Ltd. Methanol and acetonitrile (chromatographic purity) were obtained from Fisher Scientific (Fair Lawn, NJ, USA). The Milli-Q water purification system (Millipore, Bedford, MA, USA) was used to produce Ultrapure-water. All reagents were analytical grade.

Indomethacin (Indo) was purchased from Shanxi Yun-Peng Pharmaceutical. Co., Ltd. (China). The reference standard of gallic acid (>98% purity, wkq20010905), protocatechuic acid (>98% purity, wkq20020706), catechin (>98% purity, wkq20021707), epicatechin (>98% purity, wkq20012203), rutin (>98% purity, wkq20030203) were purchased from Sichuan Weikeqi Biotechnology Co., Ltd. (China). All other reagents were of analytical purity grade or better.

The reference standards of geniposidic acid (GA) and

protocatechutic acid (PCA) (purity of 98 %) were purchased from the Sichuan Weikeqi Biological Technology Co., Ltd. (Chengdu, China). Standard pinoresinol

di-O-b-D-glucopyranoside (PDG) was purchased from the

Shanghai Shunbo Biological Technology Co