Octadeca-9,12-dienyl-3,4,5-hydroxybenzoate (GA-LA) was chemically synthesized from gallic acid and linoleic acid ester, and its biological functions were tested. Radical-scavenging activity of GA-LA was comparable to those of gallic and ascorbic acids at 0.24 mM, and tyrosinase inhibition effect was higher than that of ascorbic acid. Gallic and linoleic acids did not show any tyrosinase activity. Results of cyclooxygenase (COX) inhibition effect indicate GA-LA has higher selectivity in COX-1 inhibition. GA-LA from gallic and linoleic acids could be used as functional reagent for antioxidative, skin-whitening, and anti-inflammatory effects in food, pharmaceutrical, and cosmetic industries.