Methyl eugenol dominates the leaf and floral essential oils of Ocimum tenuiflorum linn

Abstract

Ocimum tenuiflorum L., commonly known as holy basil, is an aromatic culinary and medicinal herb. The essential oils isolated from the fresh leaves and flowers of O. tenuiflorum were subjected to gas chromatography-mass spectrometry (GC-MS). The analyses facilitated the identification of twenty-three constituents in the leaf oil, accounting for 99.8% of the oil composition; thirty-five compounds were also detected in the floral oil, which amounted to 97.4% of the total oil composition. The main constituents in the leaf oil were methyl eugenol (82.9%) and germacrene D (5.1%), whereas methyl eugenol (63.6%), germacene D (9.7%), and α–α-bulnesene (5.2%) were major compounds in the floral oil. The leaf and floral oils were, respectively, predominantly composed of oxygenated components (85.7% and 69.6%) compared with hydrocarbons (14.1% and 27.8%). In addition, the percentage compositions of various classes of compounds in the leaf and floral oils were, respectively, monoterpene (0.7 and 0.9%), sesquiterpene (13.4 and 26.9%), monoterpenoid (0.8 and 1.3), sesquiterpenoid (1.5 and 4.6%), and phenylpropanoid (83.4 and 63.7%). Ocimum tenuiflorum is shown to be a potential source of methyl eugenol and could be considered as a potential natural source of methyl eugenol, with possible applications as a food preservative owing to its antioxidant and antimicrobial properties.