Efficient Synthesis of Octacosanol Linoleate Catalyzed by Ionic Liquid and Its Structure Characterization

Octacosanol, as the major active policosanol, has attracted much attention due to the potential beneficial effects for human health. However, free octacosanol has a high melting point, poor oil solubility and low bioavailability, which greatly restricts its practical application. In this study, we report a highly efficient method for an ionic liquids (IL)‐catalyzed synthesis of octacosanol ester by direct esterification with linoleic acid. The synthesized product was purified, subsequently characterized by FT‐IR, MS and NMR and finally confirmed to be octacosanol linoleate. The reaction parameters were investigated and the conversion reached 91.3 ± 4.8 % under the optimum conditions: IL 1‐butylsulfonate‐3‐methylimidazolium hydrogen sulfate ([BSO₃HMim][HSO₄]) as catalyst, IL dose 1.5 % (related to the mass of both reactants), 1:1 molar ratio of octacosanol to linoleic acid, 80 °C, and 1 h. The melting point and oil solubility of octacosanol were greatly improved by esterification with linoleic acid, facilitating the incorporation into a variety of oil‐based systems.