Nutrient antioxidants in oregano.

Oregano and its various extracts have been studied as inhibitors of autoxidation but so far the research work has focused mainly on the polar non nutrient compounds. Very little is known about the non polar fraction extracted by hexane which is also antioxidant and has been reported to suppress the mutagenicity of Trp-P-2, a dietary carcinogen. In this work four different species of oregano, Origanum vulgare subsp. hirtum, Satureja thymbra, Origanum dictamnus and Origanum onites, were extracted with hexane. The extracts were saponified and in the unsaponifiable fraction thin layer chromatography and high performance liquid chromatography were applied for the isolation, detection and determination of tocopherols. The four known homologues of tocopherol, alpha-, beta-, gamma- and delta-, were found to be present in all the samples but the concentration of the gamma-homologue was significantly higher. Total tocopherol content ranged from 288 ppm to 672 ppm.