Characterization of Essential Oil Composition in Different Basil Species and Pot Cultures by a GC-MS Method

Basil (Ocimum L.) species are used as medicinal plants due to their essential oils exhibiting specific biological activity. The present work demonstrated that both the variety and season/conditions of cultivation had a significant effect on (i) the produced amount (extraction yield), (ii) qualitative, as well as (iii) quantitative profile of basil essential oil. Among studied basil varieties, a new variety, `Manes', was characterized for the first time. Based on our quantitative evaluation of GC-MS profiles, the following chemotypes and average concentrations of a main component were detected in the studied basil varieties: `Ohre', `Lettuce Leaf', `Purple Opaal', `Dark Green' (linalool, 5.99, 2.49, 2.34, 2.01 mg/mL, respectively), and `Mammolo Genovese', `Manes', `Red Rubin'(eucalyptol, 1.34, 0.96, 0.76 mg/mL, respectively). At the same time, when considering other compounds identified in GC-MS profiles, all the studied varieties, except from `Lettuce Leaf', were methyl eugenol-rich with a strong dependence of the eugenol: methyl eugenol ratio on the seasonal changes (mainly solar irradiation, but also temperature and relative humidity). More complex and/or variable (depending on the season and cultivation) chemotypes were observed with `Lettuce Leaf'(plus estragole, 2.27 mg/mL), `Dark Green'(plus eucalyptol, 1.36 mg/mL), `Mammolo Genovese'(plus eugenol, 1.19 mg/mL), `Red Rubin'(plus linalool and eugenol, 0.46 and 0.56 mg/mL, respectively), and `Manes'(plus linalool and eugenol, 0.58 and 0.40 mg/mL, respectively). When considering superior extraction yield (ca. 17 mL.kg(-1), i.e., two to five times higher than other examined varieties) and consistent amounts (yields) of essential oil when comparing inter-seasonal or inter-year data (RSD and inter-year difference in mean yield values <2.5%), this new basil variety is very promising for use in the pharmaceutical, food, and cosmetic industries.