Comparative study of traditional essential oil and supercritical fluid extracts of Moldavian dragonhead (Dracocephalum moldavica L.)

The effectiveness and selectivity of different extraction procedures (hydrodistillation, Soxhlet extraction with organic solvents and supercritical fluid extraction) was compared. The main volatile constituents (geraniol, nerol, geranial, neral, geranyl acetate and neryl acetate) of the traditional essential oil obtained by hydrodistillation and supercritical fluid extracts of Dracocephalum moldavica L. were analysed by the gas chromatographic–mass spectrometric method. The supercritical fluid extraction was carried out using fluid carbon dioxide. Extracts were collected by stepwise precipitation in two separators. Fractioned extraction was also performed by interrupting the extraction process at determined time intervals and collecting four succesive fractions from the second separator. The main volatile constituents of the essential oil were geraniol and geranyl acetate. The supercritical extract collected at the beginning of the extraction process was richer in geranyl acetate and neryl acetate and poorer in geraniol than the conventional essential oil. Copyright © 2006 John Wiley & Sons, Ltd.