Chemical Constituents of Essential Oil of Ehretia cymosa Thonn

Abstract

The chemical constituents of essential oil obtained by hydrodistillation of the leaves of Ehretia cymosa are being reported. The essential oils were obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by gas chromatography (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The components of the essential oils were identified by comparison of their mass spectra (MS) data and linear retention indices (LRI) with literature data. The essential oil content was 0.32% (v/w), calculated on a dry weight basis. The leaves oil of E. cymosa comprised mainly of sesquiterpene hydrocarbon compounds represented mainly by trans-α-bergamotene (15.2%), α-curcumene (14.5%) and β-cedrene (14.0%). The chemical compositions of the essential oil from the leaves of the plant are being reported for the first time. Aims: The aim of this study was to report the volatile constituents identified from hydrodistilled oil from the leaves of Ehretia cymosa. Study Design: The study design involves the collection of the leaves sample and hydrodisitillation of essential oil from the plant material as well as subsequent analysis of the oil for its chemical composition. Place and Duration of Study: Mature leaves of E. cymosa were collected from Amuoloko area, Akanran, Ibadan, Oyo State, Nigeria, in May 2015. Methodology: About 600 g of air-dried plant sample was pulverized and the hydrodistillation was carried out according to the British Pharmacopoeia specifications to obtained colourless oil. The chemical constituents of the hydrodistilled oil were analyzed by using the techniques of gas chromatography (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Results: The major constituents of the essential oil were sesquiterpene hydrocarbons represented mainly by trans-α-bergamotene (15.2%), α-curcumene (14.5%) and β-cedrene (14.0%). Conclusion: The chemical constituents of essential oil of E. cymosa are being reported for the first time. The oil contained large amount of sesquiterpene compounds.