Anhydrous dichloromethane

α-Methoxy-ω-amino poly(ethylene glycol) (MeO-PEG-NH₂) (M_w = 12,000 g mol⁻¹) was purchased from NOF CORPORATION (Tokyo, Japan). ξ-Trifluoroacetyl-l-lysine N-carboxyanhydride (Lys-(TFA)-NCA) was purchased from Chuo Kaseihin Co. Inc. (Tokyo, Japan). N,N-dimethylformamide (DMF) (purity > 99.5%) and methanol (purity > 99.5%) were purchased from Fujifilm Wako Pure Chemical, Co., Inc., (Tokyo, Japan). Diethyl ether (purity > 95%), cis-aconitic anhydride (CAA; purity > 95%), dextran sulfate (M_r ~40,000), and 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) (1.0 M), Dulbecco’s phosphate-buffered saline (D-PBS), fetal bovine serum (FBS), penicillin-streptomycin and RPMI-1640 medium were purchased from Sigma-Aldrich (St. Louis, MO, USA). Oxalyl Chloride (purity > 98%) and anhydrous dichloromethane (purity > 98%) were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). The CT26 cells were obtained from Riken BioResource Center (Tsukuba, Japan).

The solvents such as methanol, isopropanol, chloroform, ammonium acetate solution (1M) of LC/MS grade, Dicyclohexyl carbodiimide, and lithium hydroxide were obtained from Wako Pure Chemical Industries, Ltd., (Osaka, Japan). 12-hydroxystearic acid, methyl ricinoleate, dry pyridine, 4-dimethylaminopyridine, and anhydrous dichloromethane were purchased from the Tokyo Chemical Industry (Tokyo, Japan). Docosahexaenoic acid with a purity ≥98% was obtained from Cayman Chemicals (Ann Arbor, MA, USA). Silica Gel N60 (40–50 μm) was obtained from Kanto Chemical Industry (Tokyo, Japan). The EquiSPLASH Lipidomix quantitative standard for mass spectrometry and oleic acid-d9 internal standards were purchased from Avanti Polar Lipids (Alabaster, AL, USA). Silica gel 60G F₂₅₄ glass plates (20 × 20 cm²) were obtained from Merck (Tokyo, Japan). The high-resolution mass measurements were performed by Linear Quadrupole Orbitrap mass spectrometer (LTQ Orbitrap XL, Thermo Fisher Scientific (San Jose, CA, USA)).

12-hydroxystearic acid, methyl ricinoleate, oleoyl chloride, linoleoyl chloride, dry pyridine, anhydrous dichloromethane, CDCl₃, and 4-dimethylaminopyridine were purchased from Tokyo Chemical Industry (Tokyo, Japan). Dicyclohexyl carbodiimide, lithium hydroxide, Methanol for LC/MS, and all other reagents of synthetic grade were obtained from Wako Pure Chemical Corporation (Tokyo, Japan). Docosahexaenoic acid and Eicosapentaenoic acid with purity ≥98%, were purchased from Cayman Chemicals (Ann Arbor, MA, USA). Thin-layer chromatography (TLC) Silica gel 60G F₂₅₄ glass plates (20 × 20 cm) were obtained from Merck (Tokyo, Japan) and spots were visualized by spraying 5% methanolic H₂SO₄. The column chromatography was performed by using spherical type Silica Gel N60 of particle size 40–50 μm, obtained from Kanto Chemical Industry (Tokyo, Japan). ¹H and ¹³C NMR spectra were acquired using 400 MHz JNM-ECX400P (JEOL, Japan). The spectra were processed using ACD/NMR software and the chemical shifts(δ) values are given in ppm. The accurate mass measurements were performed by LTQ Orbitrap XL (Thermo Fisher scientific). Low-resolution electrospray ionization mass spectra (LR-ESI-MS) was recorded by LXQ (Thermo Fisher scientific), The methyl ester of 12-hydroxystearic acid (12-HSA) was prepared by direct methylation 12-HSA by refluxing at 80 °C in methanolic 2N HCl.