*2.1. Chemicals*

2,2-Diphenyl-1-2,4,6-trinitro-phenyl hydrazine (DPPH), 2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) (≥99%), 3,4-dihydroxy-l-phenylalanine (l-DOPA) (≥98%), 6-hydroxy-2,5,7,8-tetramethylchromane-

2-carboxylic acid (Trolox) (≥97%), 2,2- -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) (≥98%), dimethyl sulfoxide (DMSO) (≥99%), ferric chloride, hydrogen peroxide 30% solution, kojic acid, mushroom tyrosinase, *<sup>N</sup>*-acetyl-l-cysteine (≥99%), phosphate buffer, *<sup>p</sup>*-nitrophenyl-β-d-glucuronide (PNPG), sodium carbonate, vanillin (99%), resazurin, neutral red, 2,7 dichloro-fluorescein diacetate (DCFH-DA), acetic acid (≥99%) were acquired from Sigma Aldrich (Schnelldorf, Germany). Acetone, Folin–Ciocâlteu reagent, hydrochloric acid (HCl) (37%), sodium phosphate (≥99%) were acquired from Merck (Darmstadt, Germany). α-Glucosidase solution (*Saccharomyces cerevisiae*, EC 3.2.1.20) was obtained from Sigma (Darmstadt, Germany). Aluminum chloride (≥98%) was acquired from Carl Roth (Karlsruhe, Germany), Dulbecco's modified Eagle medium (DMEM) from Gibco (Paisley, UK), and fetal bovine serum (FBS) from Sigma Aldrich (Steinheim, Germany).

All solvents were of LC grade and all reagents were of analytical grade.

The standards used for both spectrophotometric and liquid chromatography–mass spectrometry (LC-MS) analyses were: apigenin (≥95%), caffeic acid (≥98%), brassicasterol (≥98%), caftaric acid (≥97%), (+)-catechin (≥96%), chlorogenic acid (≥95%), (−)-epicatechin (≥90%), fisetin (≥98%), gentisic acid

(≥98%), <sup>l</sup>-glutathione (≥98%), hyperoside (quercetin 3-d-galactoside) (≥97%), isoquercitrin (quercetin 3-β-d-glucoside) (≥98%), kaempferol (≥97%), luteolin (≥98%), myricetin (≥96%), patuletin (≥98%), *p*-coumaric acid (≥98%), protocatechuic acid (3,4-dihydroxybenzoic acid) (≥97%), quercetin (≥95%), quercitrin (quercetin 3-rhamonoside) (≥78%), rutoside (quercetin-3-*O*-rutinoside) (≥97%), syringic acid (≥95%), vanillic acid (≥97%), campesterol (~65%), ergosterol (≥95%), stigmasterol (~95%) acquired from Sigma-Aldrich, ferulic acid (≥99%), gallic acid (≥98%) acquired from Merck (Darmstadt, Germany), beta-sitosterol (≥80%), sinapic acid (≥98%) acquired from Carl Roth (Karlsruhe, Germany).
