Essential Oils from Leaves, Stems and Roots of Plectranthus barbatus Andr. (Labiatae) Grown in Brazil

Abstract Essential oils from leaves, stems and roots of Plectranthus barbatus Andr.(Labiatae) were analyzed by GC/MS. The major constituents found were α-pinene (22.2%) in the leaves, β-phellandrene (26.1%) in the stems, and (Z)-β-ocimene (37.6%) in the roots. Although diterpenes were reported previously in this species, this is the first time that manool (1.0%) and abietatriene (0.7%) have been found in the leaf, and roots oils, respectively.