Chemical Constituents of the Essential Oil of Invasive Chromolaena odorata leaves in Central Nepal

Chromolaena odorata is one of the widely distributed invasive alien plants in the tropical to subtropical regions of Nepal. It has the ability to impact native species in its invaded range by multiple modes such as allelopathy including volatilization. This study aims to identify volatile chemical components in the essential oil of C. odorata. The leaf samples of C. odorata were collected from the Radha Krishna Community Forest, Chitwan district of Nepal. The essential oil from the leaves was extracted and the chemical composition of the oil was analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). A total of 19 chemical components from the oil were identified. The major components were linalool (21.64%); β-pinene (9.43%); 1,3-cycloheptadiene (8.92%); β-cubebene (7%); cinnamaldehyde (5.30%) and caryophyllene oxide (4.94%). To the best of our knowledge, the presence of o-methoxy cinnamaldehyde and isoeugenyl acetate was not listed as the chemical constituents in volatile oils of C. odorata previously. The components of the volatile oil are suspected to have an allelopathic effect on native species, anti-herbivory properties, and medicinal values. Therefore, this study could be important to understand plant invasiveness and utilization of the plant for the extraction of bioactive compounds that could contribute to control and manage the invasive plants in the invaded areas.