Arunachalam, S.S.Chandrasekar, V.Belur, P.D.2026-02-042024Food Chemistry, 2024, 441, , pp. -3088146https://doi.org/10.1016/j.foodchem.2024.138380https://idr.nitk.ac.in/handle/123456789/21124Lipophilization of natural antioxidants is a proven strategy to enhance the solubility in bulk oil systems, thereby increasing their efficacy against oxidative degradation. This study aims to synthesize esters of 3,4-dihydroxyphenylacetic acid (3,4-DHPA) using Amberlyst-15 and to study the application of these esters in refined fish oil. Lipophilic esters were synthesized by esterification and transesterification of 3,4-DHPA in various solvent systems. Esters of methanol, butanol and hexanol were obtained with percent conversion of 81.1, 69.3 and 78.8 respectively, and were subjected to molecular characterization and in vitro oxidant assays. The 3,4-DHPA and its methyl ester showed 36% reduction in the TOTOX value over 30 days of storage. The length of the acyl chain in the ester was found to exert a high influence on its efficacy and lipophilicity. This is the first report of 3,4-DHPA and its lipophilic esters studied for enhancing the oxidative stability of fish oil. © 2024 Elsevier LtdAcetic acidFishPetroleum refiningpH3,4-dihydroxyphenyl acetic acidAcid esterAmberlyst-15Bulk oil systemsFish oilLipophilizationNatural antioxidantsOxidative degradationOxidative stabilitySynthesis and characterizationsEsters3,4 dihydroxyphenylacetic acidbutanolfish oilhexanolmethanol3,4-dihydroxyphthalic acidantioxidantesterphthalic acid derivativeantioxidant activityArticlecontrolled studyesterificationferric reducing antioxidant power assayin vitro studylipophilicitysynthesistransesterificationAntioxidantsEsterificationFish OilsPhthalic Acids