Ethyl acetate etoac

Acetonitrile (ACN) and methanol (MeOH) (LC-MS grade) were purchased from Biosolve (Valkenswaard, the Netherlands). Methanol (HPLC grade) and dimethylsulfoxide (DMSO, 99.9%, for spectroscopy) were ordered from Acros Organics (Geel, Belgium). Ethyl acetate (EtOAc, 99.9%) were purchased from VWR (Haasrode, Belgium), while Chem-Lab (Zedelgem, Belgium) supplied hexane (C₆H₁₄, >99%, p.a.). Hanks’ Balanced Salt Solution without phenol red (HBSS) was ordered from Lonza (Verviers, Belgium). Merck (Darmstadt, Germany) supplied sodium hydroxide (NaOH, pellets, p.a.) and disodiumtetraborate decahydrate (Na₂B₄O₇.10H₂O, borax, 99–103%). Ritonavir (RTV) powder was purchased from Sigma-Aldrich (St. Louis, MO, USA.) for analytical purposes. Lopinavir (LPV) powder was donated by Hetero Drugs Ltd. (Hyderabad, India). Water was purified using a Maxima System (Elga Ltd., High Wycombe Bucks, UK).

Vanillin
(V) (99%), ethylene carbonate (EC)
(98%), potassium carbonate (K₂CO₃) (≥99%), N,N-dimethylformamide (DMF) (≥99%),
methacrylic anhydride (MAA) (94%), ethylenediamine (ED) (≥99%),
2,2′-(ethylenedioxy)bis(ethylamine) (Dom) (>97%), phenylbis(2,4,6-trimethylbenzoyl)phosphine
oxide (BAPO) (97%), and deuterium dimethyl sulfoxide (DMSO-d₆) (99.9% atom % D) were purchased from Sigma-Aldrich
and used without any additional purification. 4-(Dimethylamino)pyridine
(DMAP) (≥99.0%, Fluka), magnesium sulfate (99%, VWR), sodium
bicarbonate (≥99%, Merck), sodium hydroxide (NaOH) (≥99%,
Fisher Scientific), ethyl acetate (EtOAc) (≥99%, VWR), dichloromethane
(DCM) (≥99%, Fisher Scientific), hydrochloric acid (HCl) (37%),
and acetone (≥99.5%, VWR) were all used as received. Sodium
lignosulfonate for the coating of the thermosets and 2,2-diphenyl-1-picrylhydrazyl
(DPPH°) for the antioxidant assay were acquired from Tokyo Chemical
Industry Co., Ltd.

The samples were air-dried for three weeks, and then powdered by a cryo-grinder. All solvents were of analytical grade. Ethanol (EtOH) was purchased from Merck Sigma Aldrich (Darmstadt, Germany). Ethyl acetate (EtOAc) and n-butanol (n-BuOH) were purchased from VWR (Rosny-sous-Bois, France). Milli-Q water (18.2 MΩ) was generated by Millipore synergy system (Molsheim, France). Phosphate buffer solution (PBS) was prepared as follows: 137 mM sodium chloride (NaCl), 2.7 mM potassium chloride (KCl), 10 mM disodium hydrogen phosphate dihydrate (Na₂HPO_4, 2H₂O) and 1.76 mM potassium dihydrogen phosphate (KH₂PO₄).