abeo-abietanes from Teucrium polium roots as protective factors against oxidative stress

Six new 17(15→16)-abeo-abietanes, along with seven known compounds, were isolated and characterized from ethyl acetate root extract of Teucrium polium L., a medicinal plant belonging to the Labiatae family reported to have hypolipidemic, hypoglycaemic, anti-nociceptive and anti-inflammatory effects. Their structures were elucidated by 1D ((1)H, (13)C and DEPT) and 2D (COSY, TOCSY, HSQC, HMBC, and NOESY) NMR and mass spectral data. The antioxidative properties of pure metabolites were analyzed on the basis of their DPPH radical scavenging capability. The antioxidant capacity in cell-free systems of the isolated metabolites was carried out by measuring their capabilities to inhibit the synthesis of thiobarbituric acid reactive species in assay media using as oxidable substrates a vegetable fat and the pentose sugar 2-deoxyribose and to prevent oxidative damage of the bovine serum albumin (BSA) hydrosoluble protein. All of the compounds showed a significant and dose-response efficacy although weaker than that exercised by the standard Trolox®.