2 2 azobis

1-Vinylimidazole (Aldrich 99%), 2,2′-azobis(2-methylpropionitrile; AIBN, 98%), bromoacetonitrile (Aldrich 97%) and bis(trifluoromethane sulfonyl)imide lithium salt (Aldrich 99%) were used as received without further purifications. DMSO, dimethyl formamide, methanol and tetrahydrofuran were of analytic grade. Several PAA samples (MW: 2,000 g mol⁻¹, solid powder; MW: 100,000 g mol⁻¹, 35 wt% in water, MW: 250,000 g mol⁻¹, 35 wt% in water; MW: 450,000 g mol⁻¹, solid powder; MW: 3,000,000 g mol⁻¹, solid powder ) were obtained from Sigma Aldrich. Poly[1-cyanomethyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide] (PCMVImTf₂N) was prepared according to a previous report27 .

Styrene (99%, Aldrich), glycidyl
methacrylate (GMA, 99%, Aldrich), 2-cyano-2-propyl benzodithioate
(CPDB, 97%, Strem Chemicals), 2-mercaptopyridine (2MP, 99%, Aldrich),
methyl thioglycolate (MTG, 95%, Aldrich, volatile and with very unpleasant
smell!), 2,2,2-trifluoroethanethiol (TFET, 95%, Aldrich, volatile
and with very unpleasant smell!), 2,2′-azobis(2-methylpropionitrile)
(AIBN, 98%), lithium hydroxide (LiOH, 99.99%, Aldrich), tetrahydrofuran
(THF, 99.9%, Fisher Chemical), N,N-dimethylformamide (DMF, anhydrous, 99.8%, Aldrich), and diiodomethane
(CH₂I₂, 99%, Aldrich) were purchased and used
as received unless otherwise noted. LiOH aqueous solution was freshly
made before each thiol–epoxy reaction at a concentration of
approximately 20 mg mL^–1 in deionized water. Inhibitor
was removed by passing commercial Styrene and GMA monomers through
a basic alumina column prior to use. AIBN was recrystallized from
methanol twice prior to use.

Folin–Ciocalteau solution, sodium carbonate, fluorescein, 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH), (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (trolox), gallic acid, methanol (HPLC grade), acetonitrile (LC-MS grade), phosphoric acid 85%, Luperox^® TBH70X tert-butyl hydroperoxide solution (TBH), and 2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) were purchased from Sigma-Aldrich (Milan, Italy). CellTiter 96^® Aqueous One Solution Assay (MTS) was purchased from Promega (Milan, Italy). The water used in all experiments was Millipore Milli-Q.

The following chemicals and reagents were purchased from Sigma-Aldrich Italia (Milan, Italy): Folin–Ciocalteu’s phenol reagent, 6-hydroxyl-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (Trolox), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid; ABTS), AlCl₃, NaNO₂, FeCl₂, FeCl₃, FerroZine^®, fluorescein, 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH), phosphoric acid (85–87%, w/w), hydrochloric acid (37%, w/w), monobasic sodium phosphate (>98%), sodium hydroxide beads (>98%), and HPLC-grade solvents. Pure standards of phenolic acids (4-hydroxybenzoic, gallic, caffeic, chlorogenic, ferulic, p-coumaric, sinapic, syringic, trans-cinnamic, and vanillic acids) and flavonoids (quercetin, quercetin-3-O-glucoside, quercetin-3-O-rutinoside, quercetin-3-O-galactoside, kaempferol, kaempferol-3-O-rutinoside, catechin, epicatechin, daidzein, and genistein) were purchased from Extrasynthese (Genay Cedex, France). The IUPAC names for these compounds are indicated in Table S1. All standards (>99.5% purity in powder form) were prepared as stock solutions at 1 mg/mL in methanol and stored in the dark at −18 °C for less than three months.

Styrene (St) (>99%), divinylbenzene (DVB) (80%), sodium 4-vinylbenzenesulfonate (NaVBS) (>90%), ammonium persulfate (NH₄)₂S₂O₈ (APS) (>98%), 2,2′-azobis(2-methylpropionitrile) (AIBN) (>98%), ammonium hydroxide solution (NH₄·OH) (28%) and basic alumina (Al₂O₃) (≥98%), 3-(triethoxysilyl)propionitrile (TESPN) (97%), 3-(triethoxysilyl)propyl-methacrylate (TSPM) (99%), sulfuric acid (H₂SO₄) (95.0–98.0%), branched polyethyleneimine (bPEI, M_n ≈ 10,000 by GPC, M_w ≈ 25,000 by LS) and paraffin wax (mp 53–58 °C) were purchased from Sigma-Aldrich (Buchs, Switzerland). N,N’-diisopropylcarbodiimide (DIC) (99%) was purchased from Acros Organics (Basel, Switzerland). St and DVB were passed through basic alumina to remove the stabilizer before usage. AIBN was purified by re-crystallization twice from methanol and stored at −20 °C before usage. Other reagents were used as received. Ultrapure water (UPW; conductivity c = 0.055 µS/cm and resistivity, ρ = 18.2 MΩ cm at 298 K) was obtained from an Arium 611 VF water purification system (Startorius stedim biotech, Aubagne, France), and it was used as the aqueous medium in all experiments.

T2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH), fluorescein disodium salt, Folin-Ciocalteu reagent, Gallic acid, catechin, 5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), ethanol, acetone, isopropanol, hydrochloric acid (HCl) were purchase from Sigma-Aldrich. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), antimycin A, Dulbecco Modified Eagle Medium (DMEM) and Phosphate buffer saline (PBS) were purchase from Invitrogen (Waltham, MA, USA).

The following reagents were used: KH₂PO₄, Na₂HPO₄·12H₂O (Reachim, Moscow, Russia), reagent grade p.a. (buffer system); 2,2-azobis (2-methylpropionamidine) dihydrochloride (AAPH) (CAS: 2997-92-4, Sigma-Aldrich, St. Louis, MO, USA), reagent grade puriss.; phoroglucinol, pyrogallol, hydroxyquinol, gallic acid, and ascorbic acid (Sigma-Aldrich, St. Louis, MO, USA).
Solutions of the polyphenols and imidazole-derived polyphenols were prepared with distilled deionized water.
The antioxidant capacity was determined in a phosphate buffer solution (PBS) with pH 7.4. Redox transformations were investigated in 0.1 M KCl.