Content and Composition of Wild Bergamot (Monarda fistulosa L.) Essential Oil at Different Phenological Phases

Abstract

Using gas chromatography, we show that the ratio between constituents of Monarda fistulosa L. essential oil varies with the phase in plant development. Our 3-year long studies reveal that the essential oil content of wild bergamot peaks at the mass flowering phase, reaching 1.77%. This period is characterized by higher levels of α-terpineol (37.74%) and p-cyneme (4.85)—intermediate products of biosynthesis of phenolic compounds. As the plant development goes through the budding phase to the end of flowering, the thymol content increases to 48.95%, while the carvacrol content falls from 20.99 to 2.29%. We establish that the content of thymoquinone, a pharmacologically important constituent, in the essential oil of the considered plant tends to increase by the end of the flowering stage, from 3.39 to 17.65%.