Intraspecific chemical variability in essential oil of Cymbopogon distans (Nees ex Steud.) W.Watson from Uttarakhand Himalaya (India)

Abstract

The essential oil composition of ten populations of Cymbopogon distans (Nees ex Steud.) W. Watson (Family Poaceae) growing wild in Himalayan region of Uttarakhand (India) has been studied to find out possible chemotypes. Oils were analyzed using gas chromatography and gas chromatography–mass spectrometry techniques to determine the intraspecific chemical variability. Altogether, 42 constituents were identified, representing 85.54-95.72 % of the oil composition. The main constituents in the essential oils of most of the populations were piperitone (1.05-48.78 %), cis- and trans -p-menth-2-en-1-ol (0.26-39.52 %), α-terpinene (0.52-24.86 %), cis and trans -piperitol (0.52-23.19 %), limonene (2.44-12.59 %) and camphene (0.01-6.22 %). Bornyl acetate (15.52-27.87 %), β-selinene (0.24-11.45 %), β-terpineol (5.45-6.16 %) and borneol (4.78-5.72 %) were also detected in some of the populations. The results from the chemical analysis of the essential oils were subjected to chemometric cluster analysis in order to identify the marker compounds, which differentiate the groups of individuals. Based on major compounds, the populations were represented by p-menth-2-en-1-ol, piperitol, α-terpinene (chemotype I), bornyl acetate, limonene, borneol (chemotype II), piperitone and α-terpinene (chemotype III). The present analysis revealed a new chemotype, containing bornyl acetate as the major component in the essential oil of C. distans from Uttarakhand, which was not reported earlier as a chief constituent.