Apigenin 7 glucoside

All the chemicals used in this study were of analytical grade. Water was daily deionized by using a Milli-Q system from Millipore (Bedford, MA, USA). Ethanol was supplied by J.T. Baker (Deventer, The Netherlands). Methanol and acetonitrile, both of LC-MS grade, were purchased from Prolabo (Paris, France). Acetic acid and pure standards of apigenin, apigenin-7-glucoside, hydroxytyrosol, luteolin, luteolin-7-glucoside, pinoresinol, rutin, tyrosol and vanillic acid were acquired from Sigma-Aldrich (St. Louis, MO, USA); whereas oleuropein was purchased from Extrasynthese (Lyon, France).
A stock standard solution was prepared by dissolving the appropriate amount of each compound in methanol. Then, diluted working solutions were obtained at nine different concentrations (0.5 mg/L; 1 mg/L; 2.5 mg/L; 5 mg/L; 12.5 mg/L; 25 mg/L; 50 mg/L; 100 mg/L and 200 mg/L) and were stored at −20 °C. If any other concentration level was required for a particular sample or to establish the analytical parameters of the method, it was logically prepared.

PBS solution, acrylamide, N-ethylmaleimide, DTT, GSSG, eosin isothiocyanate, and 19 different flavonoids (quercetin, 3-O-methyl quercetin, isoquercetin, quercitrin, rutin, morin, rhamnetin, isorhamnetin, fisetin, apigenin, apigenin-7-glucoside, luteolin-7-glucoside, kaempferol, eupatorin, eupatorin-5-methyl-ether, genistein, naringenin, cyanidin, and 6,2′,4′-trimethoxyflavone) were purchased from Sigma-Aldrich, EDTA (0.5 M solution pH 8.0) from IBI Scientific. SYPRO Orange was from Invitrogen.

Black-seeded common beans (Phaseolus vulgaris L. cv Negro de vaina morada) were cultivated in November 2018 and collected in March 2019 in Chiapas, Mexico. Seeds were stored at 4 °C until use. Ultrapure water, ethanol (≥99%), sodium carbonate, 2 N Folin–Ciocalteu reagent, gallic acid, chlorohydric acid, potassium chloride, sodium acetate, Amberlite^® XAD-7HP, formic acid, n-hexane (≥95%), ethyl acetate (≥99.7%), methanol (≥99%), trifluoracetic acid (TFA), acetonitrile (≥99.9%), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), 6-hydroxy-2,5,7,8-tetramethylchrome-2-carboxylic acid (Trolox^®), potassium persulfate, sodium nitroprusside, Griess reagent, gallic acid (≥99%), genistein (≥98%), myricetin (≥96%), apigenin-7-glucoside (≥90%), epigallocatechin gallate (≥80%), kaempferol-3-glucoside (≥95%), quercetin-3-glucoside (≥90%), quercetin-3-D-galactoside (≥98%), delphinidin 3-O-glucoside (≥98%), malvidin 3-O-glucoside (≥98%), and petunidin-3-O-glucoside (≥98%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). iNOS inhibitor screening kit (Fluorometric) was purchased from Biovision (Milpitas, CA, USA). COX-1 (ovine) and COX-2 (human) inhibitor screening assay kits were purchased from Cayman Co. (St. Louis, MO, USA). CO₂ gases were obtained from Grupo Infra (Guadalajara, Jal., México).