Synthesis of hydrophilic glyceryl monocaffeate with economical catalyst cation‐exchange resin Amberlyst‐35

Abstract

BACKGROUND Caffeic acid (CA) has anti‐oxidation and anti‐inflammatory. However, the poor hydrophilicity of CA limits its biological activities. In this work, hydrophilic glyceryl monocaffeate (GMC) was synthesized by esterification using different caffeoyl donors (deep eutectic solvent and solid CA). Cation‐exchange resins were used as the catalysts. The effects of reaction conditions were also investigated. RESULTS The mass transfer limitation of esterification was eliminated using deep eutectic solvent. Compared with the previous catalysts (immobilized lipase Novozym 435), an economic cation‐exchange resin, Amberlyst‐35 (A‐35), showed good catalytic performance for GMC preparation. The activation energies of GMC synthesis and CA conversion were 43.71 kJ mol−1 and 43.07 kJ mol−1, respectively. The optimal reaction conditions were a temperature reaction of 90 °C, catalyst load of 7%, glycerol/CA molar ratio of 5:1 (mol mol−1), and reaction time of 24 h, which resulted in a maximum GMC yield and CA conversion of 69.75 ± 1.03% and 82.23 ± 2.02%, respectively. CONCLUSION The results of the work showed a promising alternative for the synthesis of GMC. © 2023 Society of Chemical Industry.