Technical Abstract: Effective lipophilic antioxidants were readily prepared by non-aqueous enzymatic transesterification of plant phenols with cuphea oil. Tyrosol (2-(4-hydroxyphenyl)ethanol) and hydroxytyrosol (2-(3,4-dihydroxyphenyl)ethanol), abundantly available phenols from olive oil processing byproduct, were found to be predominately acylated with capric acid (C10:0) derived from the triglyceride fraction of the Cuphea germplasm line PSR 23 (Cuphea Viscosissima × C. lanceolata). Under optimal conditions (60 degree C, 1:3 mole ratio of phenol to triglyceride) the reaction was complete within 2 h, with a >97% yield (based on phenol consumption) using immobilized Candida antarctica lipase B. The reaction products were good solvents for tyrosol or hydroxytyrosol, suggesting a facile manufacturing route not dependent on use of organic solvents or high vacuum. Phenolic derivatives were assessed for their ability to serve as antioxidants for preventing the oxidation of polyunsaturated fatty acyl groups in model membrane phospholipid vesicles. Phenolic derivatives were incorporated into single-lamellar liposomes comprised of 1,2-dioleoyl-sn-glycero-3-phosphocholine and an oxidation-sensitive fluorophoric fatty acid, and then subjected to 2,2'-azobis(2-amidinopropane) dihydrochloride-initiated oxidation. The antioxidant capacities of the cuphea-derived fatty acyl derivatives of tyrosol or hydroxytyrosol were the same as their respective derivatives prepared from decanoic acid, presumably due to the absence of natural antioxidants in cuphea oil. These biobased antioxidants may improve the oxidative stability of sensitive fatty acids in food applications.