Quercitrin

IL-6 was procured from Sigma. Antibodies to occludin, ZO-1, claudin-2, MLC-2, and MLCK were purchased from Zymed Laboratories; the other antibodies were purchased from cell signaling. Alexa 594 secondary antibodies and DAPI (4#,6#-diamidino-2-phenylindole) were purchased from Molecular Probes. SYBR-Green PCR Master Mix is ABI (catalog number 43049155; Applied Biosystems). The standard of liquiritin was purchased from Sigma-Aldrich (St. Louis, MO, USA). Nodakenin, quercitrin, arctiin, matairesinol, and icariin were purchased from Chemfaces (Hubei, China). Arctigenin was purchased from MUST (Chengdu Must Bio-Technology Co., Ltd., Chengdu, China). Angoroside C, neolicuroside, (8S, 8′′R)-8-(4-hydroxy-3-methoxybenzyl)-8′′-(3′,4′-dimethoxybenzyl)-γ-butyrolactone 4-O-(β-D-glycopyranoside), and emodin 8-O-β-D-glucopyranoside 8 were obtained from Chungnam National University (Daejeon, Korea). The purity of the standards was all above 95%. HPLC grade acetonitrile was purchased from J. T. Baker Inc. (Philipsburg, NJ, USA) and acetic acid purchased from JUNSEI (Junsie Chemical Co., Ltd., Tokyo, Japan). Ultrapure water was prepared by Puris-Evo-UP Water System with Evo-UP Dio VFT and Evo-ROP Dico20 (Mirae ST Co., Ltd., Anyang, Gyeonggi-do, Korea). Ultrapure water (UW) was prepared with a resistivity of 18.2 MΩ cm⁻¹ (Puris, Esse-UP Water System, Mirae ST Co., Anyang, Korea).

All plant samples were collected from Goesan-gun (Chungcheongbuk-do, Republic of Korea) in 2015 and were immediately cleaned, ground, lyophilized, and stored at −20 °C before use. Lipase from porcine pancreas type II, 4-methylumbelliferyl oleate (4-MUO), and quercetin (≥95%) was purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). Kaempferol (≥98.3%), myricitrin (≥98.3%), quercitrin (≥98.5%), and avicularin (≥99.3%) were purchased from ChemFaces Biochemical Co. (Wuhan, Hubei, China), and their purity was confirmed analytically by proton nuclear magnetic resonance (¹H-NMR) and HPLC. Methanol, n-hexane, and ethyl acetate (EtOAc) were purchased from Daejung Chemicals & Metals Co. (Siheung-si, Gyeonggi-do, Republic of Korea), and were of analytical grade. Water and acetonitrile purchased from J. T. Baker Co. (Phillipsburg, NJ, USA) were of high-performance liquid chromatography (HPLC) grade. The acetonitrile was dehydrated by molecular sieves 4 Å (Sigma-Aldrich Co.) and filtered through a membrane filter (0.45 µm) before use. All of the other chemicals were of extra-pure grade.