Galactites is a genus of flowering plants belonging to Asteraceae family. This genus is mainly represented by the Galactites elegans (All.) Nyman ex Soldano, the milky thistle, a plant of Mediterranean origin. Galactites elegans is consumed as a monofloral boar thistle honey. Chromatography separation of CHCl3 and n-BuOH extracts of aerial parts of G. elegans led to isolation of 18 pure compounds. Their structures were elucidated by 1D-and 2D-NMR spectroscopy and confirmed by mass spectrometry analysis. Sinapic aldehyde, abietin, chlorogenic acid, neochlorogenic acid, 8 alpha-ahydroxypinoresinol, 9 alpha-hydroxypinoresinol, pinoresinol, 4-ketopinoresinol, nortrachelogenin, and erythro-guaiacylglycerol-beta-O-4'-dihydroconiferyl alcohol were isolated from CHCl3 extract, while luteolin 4'-O-glucuronide, naringenin-7-O-neohcsperidoside, kaempferol-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside, apigenin-7-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside, quercitrin, quercetin-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside, ciwujiatone, and nortrachelogenin-4,4'-di-O-beta-D-glucopyranoside were obtained from n-BuOH extract. The majority of isolated compounds displayed a significant antioxidant potential in vitro test (DPPH). The ability of compounds to reduce the level of peroxides in control and BHP-treated Jurkat cells was studied. The lignan derivatives were also able to reduce at 50 mu M the basal level of peroxides in Jurkat cells as well as counteract peroxide increase induced by BLIP treatment. Particularly 8 alpha-hydroxypinoresinol was the most active showing 70% of peroxide level inhibition.