A series of new model of lipophilized phenolic compound derived from the rosmarinic acid was synthesized: 1,2-diacylglycerol rosmarinate (RDAG) with different alkyl chain lengths from ¿ve to eighteen carbons. These RDAG were obtained through a chemo-enzymatic synthesis: A chemical esteri¿cation based on the Mitsunobu reaction, followed by a lipase-catalyzed transesteri¿cation to link the different lipophilic moieties. The antioxidant abilities of these molecules were assessed on reactive oxygen species (ROS) overexpressing ¿broblasts. The RDAG 12 displayed the best antioxidant activity of the series. Lengthening of the lipid chain beyond twelve carbon atoms leads to a decrease in the antioxidant activity, thus con¿rming the occurrence of a cut-off effect. Antioxidant RDAG 12 activity was then compared with that of vitamins C and E, rosmarinic acid and decyl rosmarinate (R 10 ). The order of activity was R 10 > RDAG 12 > RDAG 5 > rosmarinic acid ¿ vitamin C ¿ vitamin E. At 5 mM, R 10 exhibited an even better antioxidant activity than the combination of vitamins C and E at 5 mM each. These results con¿rm, ¿rstly, that catechol structure is very effective in terms of antioxidant activity and secondly, that linking an appropriate hydrophobic domain is a powerful strategy to synthesize effective antioxidants. Practical applications: Phenolic compounds (especially phenolic acids and ¿avonoids) are potent antioxidants that may play an important role as well in biological system (to prevent some risk factors associated with cancers, cardiovascular, and neurodegenerative diseases) as in formulated-lipid dispersions. However, their activity is often limited by low solubility and stability in such systems. Lipophilization of phenolic compounds may increase their solubility in lipophilic matrices, conferring better antioxidant protection for food or non-food application. In biological system, lipophilization may contribute to easier penetration of antioxidants through lipid bil