Essential oil composition of purple basils, their reverted green varieties (Ocimum basilicum) and their associated biological activity

Essential oils provide the characteristic aroma notes to basil varieties and are partially responsible for basil biological activities. The search for new aromas and biological activities are important steps to find new applications for industrial crop and products. The objective of this study was to evaluate the chemical composition of the essential oils from purple basil varieties and their progeny that reverted to green varieties, and to compare the composition of these oils with other nonpigmented basil varieties. This work also evaluated selected biological activities of some of these green and basil varieties in search of new biological activities. The green purple varieties derived from Dark Opal and Osmin Purple varieties exhibited a remarkable similarity, suggesting that these plants reverted to the same green ancestor. Their aromatic volatile oils and their main components exhibited a wide range of antioxidant and antimicrobial activities, with several chemotypes (Sweet, Osmin Purple basils) expressing high antioxidant and antimicrobial activities. Some of the reverted green types, showed higher levels phenylpropanoids (e.g. higher in eugenol) compared with their parent types (Purple Ruffles). These biological activities of the aromatic oils appear to be related to their phenolic constituents and concentration of the oils (e.g. eugenol, methyleugenol). The results showed that the essential oils of these basils have a number of additional attributes and applications for the nutraceutical industry in addition to their aroma and flavor impact.