Physicochemical characteristics of the essential oils of Baccharis dracunculifolia and Baccharis uncinella D.C. (Asteraceae)

The essential oils of Baccharis dracunculifolia and Baccharis uncinella, which were obtained by hydrodistillation, were physically and chemically characterized for their yield, relative density (d2020), refraction index, solubility in ethanol and chemical composition through gas chromatography coupled to mass spectrophotometry (GC/MS). The results showed a yield of 1.5 and 1.65 mL/100g-1, relative density (d2020) of 0.9151 and 0.9147, refraction index of 1.4593 and 1.4602, rotatory power of +1.99 and +2.18. Solubility in 70% ethanol was 3.0, in 80% ethanol was 1.0 and in 96.5% ethanol was 1.0, for the oils of B. dracunculifolia and B. uncinella respectively. The evaluations in gas chromatography coupled to mass spectrophotometry showed that the oils studied are similar, presenting 26 constituents among which β-pinene, e-nerolidol, limonene and spathulenol are highlighted.