Antioxidative Effect of the Constituents of Rosemary (Rosmarinus officinalis L.) and Their Derivatives

Abstract

Antioxidative activity was measured on extracts of rosemary (Rosmarinus officinalis L.), one of the herb spices belongs to the Family Labiatae, using different solvents. Strong activity was observed in the weakly acidic fraction of the n-hexane extract, which was further fractionated and purified to afford several active compounds. An ordorless and colorless compound, named rosmanol, showed high antioxidative activity in both lard and linoleic acid, and particularly in lard, was about four times more active than synthetic antioxidants, such as BHT and BHA. Furthermore, the antioxidant activities of the derivatives of rosmanol and carnosol were measured by the ferric thiocyanate method and the TBA method, to observe the correlation between chemical structure and activity as an antioxidant.