Reversed-phase preparative HPLC analysis of the methanol extract of the seeds of Ilex aquifolium afforded two antioxidant phenylacetic acid derivatives, 2,4-dihydroxyphenylacetic acid (1) and 2,4-dihydroxyphenylacetic acid methyl ester (2). The structures were determined by spectroscopic methods. In the DPPH assay for antioxidant activity, the IC50 values of 1 and 2 were 1.50 x 10-3 and 2.55 x 10-3 mg mL-1, respectively, compared to 2.88 x 10-5 mg mL-1 of quercetin, a natural antioxidant.Reverzno-faznom preparativnom HPLC analizom metanolnog ekstrakta sjemenki biljke Ilex aquifolium izolirana su dva derivata feniloctene kiseline s antioksidativnim učinkom, 2,4-dihidroksifeniloctena kisleina (1) i metilni ester 2,4-dihidroksifeniloctene kiseline (2). Njihove strukture određene su spektroskopskim metodama. U DPPH testu na antioksidativno djelovanje, IC50 vrijednosti spojeva 1 i 2 bile su 1.50 x 10-3 i 2.55 x 10-3 mg mL-1, dok je IC50 prirodnog antioksidansa kvercitina bila 2.88 x 10-5 mg mL-1
