N 1 naphthyl ethylenediamine ned

All chemicals were of the highest purity available (>90%) and used as received. All aqueous solutions were prepared by employing deionized water (conductivity < 0.1 mS cm⁻¹). Polyoxyehthylene sorbitan monolaurate (Tween 20, ρ = 1.11 g/mL) and the coupling agent N-(1-naphthyl) ethylenediamine (NED) were purchased from Acros Organics. The coupling agent NED and the antioxidants (+)-δ-TOCoferol (90%, MW = 402.7 g/mol) and (±)-α-TOCoferol (96%, MW = 430.72 g/mol) were from Sigma-Aldrich (St. Louis, MO, USA).
The soybean and olive oils were purchased from a local supplier and stripped from their endogenous antioxidants by washing them with a 0.5 M NaOH solution and passing them twice through an activated Al₂O₃ column. The absence of endogenous antioxidants was checked by HPLC, according to standard procedures (IUPAC method 2.432). 4-Hexadecylbenzenediazonium tetrafluoroborate, 16-ArN₂BF₄, was prepared from 4-hexadecylaniline (Aldrich, 97%) by diazotization with butyl nitrite in acidic solution, as described elsewhere [30 (link)].

Tween 80, citric acid, and N-(1-naphthyl) ethylenediamine (NED) were purchased from Acros Organics (Fair Lawn, NJ, USA). Mili-Q grade water was employed in all experiments. Commercial fish oil (generously provided by Biomega Natural Nutrients S.L., Boiro, Spain) was stripped from endogenous antioxidants by passing it twice through a Al₂O₃ column under nitrogen [28 (link)]. The fatty acid composition of the fish oil, expressed as % total fatty acids, was 52% PUFAs (among others 16% EPA, 29% DHA), 25% MUFA (monounsaturated fatty acids), and 23% SFA (saturated fatty acids). Hydroxytyrosol was purchased from Seprox Biotech (Murcia, Spain). HT esters (Figure 1; acetate, HT2; hexanoate, HT6, octanoate, HT8; dodecanoate HT12; and hexadecanoate HT16) were prepared according to Almeida et al. [27 (link)]. 4-Hexadecylbenzenediazonium tetrafluoroborate, 16-ArN₂BF₄, was prepared from 4-hexadecylaniline (Aldrich, 97%) [17 (link)].

Citric acid, nonionic surfactant Tween 80 (HLB = 15.0) and N-(1-naphthyl) ethylenediamine (NED) were purchased from Acros Organics. Mili-Q grade water was employed in the preparation of emulsions. Commercial fish oil (generously provided by Biomega Natural Nutrients S.L., Boiro, A Coruña, Spain) was stripped from endogenous AOs by passing it twice through a Al₂O₃ column. The fish oil fatty acid composition, expressed as % total fatty acids, was 55% PUFAs containing 17% EPA and 30% DHA, 23% monounsaturated fatty acids (MUFA), and 22% saturated fatty acids (SFA).
The synthesis and purification of chlorogenic fatty acid esters were carried out according to the procedure described by Meirelles et al. [22 (link)]. The purity of all synthetized compounds was higher than 97%. The chemical probe 4-hexadecylbenzenediazonium tetrafluoroborate, 16-ArN₂BF₄, was prepared according to the procedure described by Bravo–Diaz et al. [19 (link)].