Leucas aspera (Willd.) Link Essential Oil from India: β-Caryophyllene and 1-Octen-3-ol Chemotypes

Abstract

Leucas aspera (Willd.) Link (Lamiaceae) is an annual, branched herb used in traditional medicine as an antipyretic and insecticide. The hydro-distilled essential oil was obtained from the aerial parts of L. aspera growing wild in North West Karnataka region of India and analyzed by gas chromatography equipped with flame ionization detector and gas chromatography coupled with mass spectrometry. Forty-three compounds were identified, representing 98.1% of the total oil. The main constituents were identified as β-caryophyllene (34.2%), 1-octen-3-ol (14.8%), α-humulene (6.3%), α-pinene (5.8%), epi-α-bisabolol (4.6%) and limonene (4.5%). The oil was found to be rich in sesquiterpene hydrocarbons (47.7%), followed by others (long chain hydrocarbons (LCH), oxygenated LCH and phenyl derivative constituents) (20.2%), monoterpene hydrocarbons (14.8%), oxygenated sesquiterpenes (14.8%) and oxygenated monoterpenes (0.6%) type compounds.