Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

The antioxidant activity of a triterpenoid glycoside [3-O-(β-D- glucopyranosyl)-hederagenin; OGH] isolated from the berries of Hedera colchica, an ivy species endemic in Georgia, was investigated. The antioxidant properties of OGH were evaluated using different antioxidant assays: 1,1-diphenyl-2-picryl- hydrazyl free radical (DPPH-) scavenging, total antioxidant activity, reducing power, superoxide anion radical (O2-) scavenging, hydrogen peroxide (H2O2) scavenging and metal chelating activities. The total antioxidant activity was measured according to the ferric thiocyanate method. α-Tocopherol and trolox, a water-soluble analogue of tocopherol, were used as reference antioxidant compounds. At a 30 μg/mL concentration, the inhibitory effects of OGH on the peroxidation of linoleic acid emulsion was found to be 95.3%, whereas α-tocopherol and trolox exhibited 88.8% and 86.2% inhibition of peroxidation in the system, respectively. In addition, OGH had effective DPPH- scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, total reducing power and metal chelation of ferrous ions activities. These various antioxidant activities were compared with α-tocopherol and trolox.